Our domestic same-store sales were an impressive 13.6% this quarter on top of last year's very strong 12.3%.
Our growth rates for retail and commercial were both strong with domestic commercial growth impressively north of 29%.
Commercial set a first quarter record with $900 million in sales.
And now we've delivered $900 million in sales in one quarter, an incredible accomplishment.
On a trailing four quarter basis, we had over $3.5 billion in annual commercial sales versus $2.8 billion a year ago, up 27%.
We also set a record in average weekly sales per store for any quarter, reaching over $14,400 versus $11,500 just last year.
On a two year basis, our sales accelerated from last quarter, exceeding 40%.
We ran a 9% comp this quarter on top of last year's 12.7%.
While our DIY two year stack comp decelerated slightly from our fourth quarter, it's remarkable to reflect on a more than 20% two year comp in this sector of our business.
From the data we have available to us, we continue to not only retain the enormous 10% share gains we built during the initial stages of the pandemic, but modestly build on those gains.
Given the dynamics of the past 20 months, we like others who benefited from the pandemic, believe it is more instructive to look at two year stacked comps.
For Q1, our two year comp was 25.8% and the four week periods of the quarter increased by 26.3%, 26% and 25.3% respectively.
Regarding this quarter's traffic versus ticket growth in retail, our traffic was up 1%, while our ticket was up 7.5%.
While last quarter we saw roughly 400 basis point gap in comp performance between the Northeast and Midwestern markets versus the remainder of the country, we did not see that gap this quarter.
Our same-store sales were up 13.6% versus last year's first quarter.
Our net income was $555 million.
And our earnings per share was $25.69 a share, increasing an impressive 38.1%.
This quarter, we saw our sales impacted positively by about 4% year-over-year from inflation, while our cost of goods was up about 2% on a like-for-like basis.
For the quarter, total auto part sales, which includes our domestic, Mexico and Brazil stores, were $3.6 billion, up 16.2%.
Starting with our commercial business, for the first quarter, our domestic DIFM sales increased 29.4% to $900 million and were up 41% on a two year stack basis.
Sales to our DIFM customers represented 25% of our total sales.
And our weekly sales per program were $14,400, up 25% as we averaged $75 million in total weekly commercial sales.
Once again, our growth was broad-based as national and local accounts both grew over 25% in the quarter.
We now have our commercial program in approximately 86% of our domestic stores, and we're focused on building our business with national, regional and local accounts.
This quarter, we opened 32 net new programs, finishing with 5,211 total programs.
We now have 62 mega hub locations and we expect to open approximately 16 more over the remainder of the fiscal year.
As a reminder, our mega hubs typically carry roughly 100,000 SKUs and drive tremendous sales lift inside the store box as well as serve as a fulfillment source for other stores.
These assets continue to outperform our expectation, and we would expect to open significantly more than 110 locations we have previously targeted.
On the retail side of our business, our domestic retail business was up 9% and up 21.4% on a two year stack.
During the quarter, we opened two new stores in Mexico to finish with 666 stores and one new store in Brazil to finish with 53.
With approximately 10% of our store base now outside the U.S. and our commitment to continue expansion in a disciplined way, international growth will be an attractive and meaningful contributor to AutoZone's future growth.
For the quarter, our gross margin was down 65 basis points, driven primarily by the accelerated growth in our commercial business where the shift in mix coupled with the investments in our initiatives drove margin pressure, but increased our gross profit dollars by 14.9%.
I mentioned on last quarter's call that we expected to have our gross margin down in a similar range this quarter as we saw in the fourth quarter of last fiscal year where we were down 82 basis points.
Our expenses were up 10.4% versus last year's Q1 as SG&A as a percentage of sales leverage of 171 basis points.
EBIT for the quarter was $754 million, up 22.6% versus the prior year's quarter, driven by strong top-line growth.
Interest expense for the quarter was $43.3 million, down 6.3% from Q1 a year ago as our debt outstanding at the end of the quarter was just under $5.3 billion versus just over $5.5 billion last year.
We're planning interest in the $45 million range for the second quarter of fiscal 2022 versus $46 million in last year's second quarter.
For the quarter, our tax rate was 21.9% versus 22.2% in last year's first quarter.
This quarter's rate benefited 159 basis points from stock options exercised, while last year it benefited 134 basis points.
For the second quarter of fiscal 2022, we suggest investors model us at approximately 23.6% before any assumption on credits due to stock option exercises.
Net income for the quarter was $555 million, up 25.5% versus last year's first quarter.
Our diluted share count of 21.6 million was lower by 9.1% from last year's first quarter.
The combination of higher earnings and lower share count drove earnings per share for the quarter to $25.69, up 38.1% over the prior year's first quarter.
For the first quarter, we generated approximately $800 million of operating cash flow.
Regarding our balance sheet, we now have nearly $1 billion in cash on the balance sheet and our liquidity position remains strong.
We're also managing our inventory well, as our inventory per store was up 10% versus Q1 last year.
Total inventory increased 3% over the same period last year, driven by new stores.
Net inventory, defined as merchandise inventories less accounts payable on a per store basis, was a negative $207,000 versus negative $99,000 last year and negative $203,000 last quarter.
As a result, accounts payable as a percent of gross inventory finished the quarter at 129.4% versus last year's Q1 of 114.1%.
We repurchased $900 million of AutoZone's stock in the quarter.
As of the end of the fiscal quarter, we had approximately 20.7 million shares outstanding.
At quarter end, we had just over $1 billion remaining under our share buyback authorization and just under $700 million of excess cash.
The powerful free cash we've generated this quarter allowed us to buy back approximately 2.5% of the shares outstanding at the beginning of the quarter.
We bought back over 90% of the shares outstanding of our stock since our buy back inception in 1998, while investing in our existing assets and growing our business.
We expect to maintain our long-term leverage target in the 2.5 times area and generate powerful free cash flows that will enable us to invest in the business and return meaningful amounts of cash to shareholders.
To wrap up, we had another very strong quarter, highlighted by strong comp sales, which drove a 25.5% increase in net income and a 38.1% increase in EPS.
From July 4, 1979 when our first store opened in Forest City, Arkansas, customer service has been paramount to our success.
We are also targeting to open 16 more new domestic mega hubs in the U.S. that will enhance our availability and support growth in our retail and commercial businesses.
For the fiscal year, we will open more than 200 new stores throughout the Americas with notable acceleration in our Brazil business.
Our company, our customers, our leadership team, and in particular, our AutoZoners have greatly benefited from Mark's 19 years of remarkable service.

Summary:
Our domestic same-store sales were an impressive 13.6% this quarter on top of last year's very strong 12.3%.
Our same-store sales were up 13.6% versus last year's first quarter.
And our earnings per share was $25.69 a share, increasing an impressive 38.1%.
The combination of higher earnings and lower share count drove earnings per share for the quarter to $25.69, up 38.1% over the prior year's first quarter.