Through the quarter, we operated thoughtfully with the physical and mental well-being of our employees the top priority as our 50,000-plus GPC teammates are the core of our success.
Total sales for the quarter were $4.5 billion, up 9% from last year and significantly improved from the 1% sales decrease in the fourth quarter of 2020.
These results drove a 41% increase in operating profit and an 8.1% operating margin, which is up 180 basis points from the first quarter of last year.
Our strong operating performance drove net income of $218 million and diluted earnings per share of $1.50, up 88%.
Automotive represented 66% of total sales in the first quarter and Industrial was 34%.
By region, 73% of revenues were attributable to North America with 16% in Europe and 11% in Asia-Pac.
Total sales for Global Automotive were $3 billion, a 14% increase from 2020 and much improved from a 1% increase in Q4 of 2020.
Comp sales were up 8%, improved from a 2% decrease in the fourth quarter and segment profit margin was up 250 basis points, driven by strong operating results in each of our automotive operations.
Sales were driven by positive sales comps across all our operations with 15% comps in Europe and Asia-Pac, 7% comps in the US and 3% comps in Canada.
Retail sales, which represent over 40% of our total sales volume through our Repco stores continued to outperform posting a 33% increase in March and plus 24% in the quarter.
In North America comp sales in the US were up 7% helping this business post a 180-basis point increase in profit margins.
Comp sales were up 3% and operating margin was up 130 basis points.
This is notable as this region of the US has been most affected by the COVID-19 lockdowns over the past 13 months.
We would also call out our ongoing omnichannel investments and the increase in B2C online sales, which reached record levels in the quarter and were up 150% from the prior year.
We expect further improvement in aftermarket fundamentals such as increased miles driven, a growing vehicle fleet and an increase in vehicles aged six to 12 years, all favorable for the industry.
Total sales for this group were $1.5 billion, flat with last year.
Comp sales were down 2%, improved from the 4% decrease in Q4 and reflecting the third consecutive quarter of improving sales trends.
March was a breakout month with the North American Motion team posting a 7% increase in average daily sales and achieving record sales volumes.
For perspective, PMI was 64.7% in March, an increase of 4.2 points from December 31st.
In addition, industrial production increased by 2.5% in the first quarter, the third consecutive quarter of expansion, following the significant downturn in the second quarter of 2020.
The strengthening sales environment, along with our initiatives to drive growth and control cost produced an 80 basis point margin improvement with segment profit margin at 8.3% versus 7.5% last year.
That said, we are seeing more pricing activity and expect another year of 1% to 2% price inflation from our suppliers.
Since 1928, we have been giving back to communities and causes that make a difference and that legacy continues in 2021.
In addition, in 2021, the US automotive team adjusted compensation programs to better align incentives with profitable growth.
One solid example is the success the US Industrial team enjoyed with recent facility automation investments that delivered a 500% labor productivity improvement.
A few select highlights include the alignment of talent 100% dedicated to developing and executing EV strategies, product and category management strategies with existing and new SKUs, global supplier councils with existing strategic partners, advisory groups leveraging our 25,000 global repair center relationships and partnerships with strategic EV market participants.
Total GPC sales were $4.5 billion in the first quarter, up 9% from last year and improved from the 0.7% decrease in the fourth quarter.
Gross margin was 34.5%, a 60-basis point improvement compared to 33.9% in the first quarter last year.
Our selling, administrative and other expenses were $1.2 billion in the first quarter, up 4.6% from last year, or up 5.3% from last year's adjusted SG&A.
This reflects an improvement to 26.8% of sales this year, which is down nearly 100 basis points from 27.7% last year.
Our total operating and non-operating expenses were $1.3 billion in the first quarter, up 2.2% from last year or up 2.1% compared to last year's adjusted expenses.
First quarter expenses include the benefit of approximately $20 million related to gains on the sale of real estate and favorable retirement plan valuation adjustments that are recorded to the other non-operating income line.
All in, our total expenses for the quarter improved to 28.1% of sales, down 190 basis points from 30% in 2020.
Total segment profit in the first quarter was $361 million, up a strong 41% on the 9% sales increase.
And our segment profit margin was 8.1% compared to 6.3% last year, a 180 basis point increase.
In comparison to 2019, our segment profit margin has improved by 100 basis points.
Our net interest expense of $18 million was down from $20 million in 2020 due to the decrease in total debt and more favorable interest rates relative to last year.
The corporate expense line was $31 million in the quarter, down from $55 million in 2020 due primarily to the favorable real estate gains and retirement plan adjustment discussed earlier.
Our tax rate for the first quarter was 23.8% in line with the reported rate last year and improved from the prior year adjusted rate of 26.5%.
Our first quarter net income from continuing operations was $218 million with diluted earnings per share of $1.50.
This compares to $0.84 per diluted share in the prior year or an adjusted diluted earnings per share of $0.80 for an 88% increase.
Our Automotive revenue for the first quarter was $3 billion, up 14% from the prior year.
Segment profit of $236 million was up a strong 65% with profit margin at 8% compared to 5.5% margin in the first quarter last year.
The 250 basis point increase in margin was driven by the continued recovery in the Automotive business and the execution of our growth and operating initiatives.
In addition, we're encouraged that our first quarter margin also compares favorably to the first quarter of 2019, up 120 basis points.
Our Industrial sales were $1.5 billion in the quarter, flat with last year and improved sequentially for the third consecutive quarter, which is consistent with the strengthening industrial economy.
Our segment profit of $125 million was up 10% from a year ago and profit margin was up 80 basis points to 8.3% compared to 7.5% last year.
The improved margin for Industrial reflects the third consecutive quarter of margin expansion in both our North American and Australasian industrial businesses and it's also up by 90 basis points from the first quarter of 2019.
At March 31st, total accounts receivable is down 27% from last year, which is primarily a function of the $800 million in receivables sold in 2020.
Our inventory was up 6% from the prior year and accounts payable increased 14%.
And our AP to inventory ratio improved to 124% from 116% in the last year.
Our total debt is $2.6 billion at March 31, down $1 billion or 28% from last March and down $60 million from December 31st of 2020.
With these positive changes to our debt structure, our total debt to adjusted EBITDA has improved to 1.8 times from 2.5 times last year.
Additionally, we closed the first quarter with $2.6 billion in available liquidity, which is up from $1.1 billion at March 31st last year and in line with December 31st.
We also continue to generate strong cash flow, generating $300 million in cash from operations in the first quarter, which is up from $28 million in the first quarter last year.
With a strong start to the year, including the increase in net income and the improvement in working capital, we continue to expect cash from operations to be in the $1 billion to $1.2 billion range and free cash flow of $700 million to $900 million.
We invested $48 million in capital expenditures in the first quarter, an increase from $39 million in 2020.
We continue to expect total capital expenditures of approximately $300 million for the year.
In the first quarter we paid a cash dividend of $114 million to our shareholders.
The Company has paid a cash dividend to shareholders every year since going public in 1928 and our 2021 dividend of $3.26 per share represents our 65th consecutive annual increase in the dividend.
We have actively participated in a share repurchase program since 1994.
While there were no repurchases in the first quarter, the Company is currently authorized to repurchase up to 14.5 million additional shares and we will resume share repurchases in the months and quarters ahead.
With these factors in mind, we expect total sales for 2021 to be in the range of plus 5% to plus 7%, an increase from our previous guidance of plus 4% to plus 6%.
By business, we are guiding to plus 5% to plus 7% total sales growth for the Automotive segment, an increase from plus 4% to plus 6% and a total sales increase of plus 4% to plus 6% for the Industrial segment, an increase from plus 3% to plus 5%.
On the earnings side, we are raising our guidance for diluted earnings per share to a range of $5.85 to $6.05, which is up 11% to 15% from 2020.
This represents an increase from our previous guidance of $5.55 to $5.75.

Summary:
Our strong operating performance drove net income of $218 million and diluted earnings per share of $1.50, up 88%.
In addition, in 2021, the US automotive team adjusted compensation programs to better align incentives with profitable growth.
Total GPC sales were $4.5 billion in the first quarter, up 9% from last year and improved from the 0.7% decrease in the fourth quarter.
Our first quarter net income from continuing operations was $218 million with diluted earnings per share of $1.50.
With a strong start to the year, including the increase in net income and the improvement in working capital, we continue to expect cash from operations to be in the $1 billion to $1.2 billion range and free cash flow of $700 million to $900 million.
With these factors in mind, we expect total sales for 2021 to be in the range of plus 5% to plus 7%, an increase from our previous guidance of plus 4% to plus 6%.
By business, we are guiding to plus 5% to plus 7% total sales growth for the Automotive segment, an increase from plus 4% to plus 6% and a total sales increase of plus 4% to plus 6% for the Industrial segment, an increase from plus 3% to plus 5%.
On the earnings side, we are raising our guidance for diluted earnings per share to a range of $5.85 to $6.05, which is up 11% to 15% from 2020.