Our PG&A business grew nearly 50% during the quarter, with all segments and categories up significantly year over year.
And our international business was also strong, with sales increasing 59% as countries impacted by the pandemic slowly began to reopen.
First-quarter North American retail sales were up a robust 70%, continuing the unprecedented levels of growth.
We continue to see an expanding customer base, with new customers growing 70% in Q1.
And the continued growth in sales to our existing owners, which increased an impressive 40% year over year, reinforces our confidence that these customers will return.
As I indicated earlier, our ORV business gained over 4 percentage points of market share in the first quarter.
Both Indian and Slingshot's first-quarter retail was strong as well, collectively finishing up over 70% and market share increased about 3 percentage points.
Snowmobile sales were strong as well, with retail up low 20% range for the first quarter.
While our Snowmobile business is one of our smaller product lines today, it is where we started over 66 years ago in Northern Minnesota.
The North American snowmobile industry concluded its strongest season in over a decade, with industry retail up approximately 16%.
Polaris retail eclipsed the market, growing in the mid-20% range, resulting in market share gains of over two points for the season, the best share position in 16 years.
During the 2020, 2021 selling season, new customers represented over 60% of the sales growth, nearly double the rate from the prior season ending March 2020.
Attendance was up almost 80% compared to 2020.
During the meeting, we introduced 22 new snowmobiles on the revolutionary Rider-First Matryx Platform, which delivers industry-leading ride and handling, both on and off trail.
This new engine uses proprietary SmartBoost technology for unrivaled combustion stability, enabling 10% more power at sea level and 50% more power at 10,000 feet than our current 850 Patriot engine.
Inventory levels declined further on a sequential basis and were down 71% year over year, with ORV realizing the most significant decline.
By the end of the year, we expect to be almost halfway to our goal of approximately $200 million of gross savings.
First-quarter sales were up 39% on a GAAP and adjusted basis versus the prior year.
First-quarter earnings per share on a GAAP basis was $2.11.
Adjusted earnings per share was $2.30, which was up significantly over last year's first quarter.
Adjusted gross margins were up 352 basis points year over year primarily due to the lower promotional costs driven by the strong retail demand and lower floor-plan financing costs as a result of the low dealer inventory levels.
Operating expenses as a percentage of sales were down 584 basis points as we realized leverage from the strong sales growth and the timing of some R&D expenses and stock-based compensation costs being delayed into the coming quarters.
Income from financial services declined 18% during the quarter as income from the Polaris Acceptance joint venture, which dealers use to finance their inventory, continue to be down due to the lower level of inventory in the channel.
ORV & Snowmobiles increased 50%.
global adjacent markets was up 27%.
And boats increased 29% for the quarter.
International sales were up 59% during the quarter.
About 10 points of the growth came from improved currency rates.
And our parts, garments and accessories sales increased 49% during the quarter.
Moving on to our revised guidance for 2021.
Given the stronger-than-anticipated performance in the first quarter, we have increased our total company sales growth guidance and now expect sales to increase in the 18% to 21% range for the year, up from the 13% to 16% we guided in January.
We are also increasing our full-year adjusted earnings per share guidance for 2021 and now expect earnings to be in the range of $9 to $9.25 per diluted share.
We now anticipate that gross profit margins will be down 60 to 90 basis points, primarily driven by ongoing negative product mix we saw in the first quarter, along with increased logistics and manufacturing inefficiencies due to the high level of rework in our factories.
While our gross profit margins are expected to be down for the year, as I stated on our last earnings call, if you exclude the impact of tariffs and supply chain disruptions, our gross profit margin rate would be up over 200 basis points compared to last year.
Adjusted operating expenses are now expected to improve 80 to 100 basis points as a percentage of sales as sales growth outpaces operating expense growth.
We expect operating expenses in each of the remaining three quarters to be approximately 10% to 15% above Q1 given the timing of spending.
First-quarter operating cash flow finished at $56 million compared to a negative $71 million in the first quarter of last year.
Our bank leverage ratio improved sequentially to approximately 1.3 times as our debt levels continue to decline as anticipated.
During the first quarter, we spent almost $300 million on share repurchases.
Of the $300 million spent, $130 million was generated from the exercise of options.
Our expectations for capital expenditures of approximately $250 million remain unchanged.
And on January 28, the board of directors approved a 2% increase in the regular quarterly cash dividend, which is the 26th consecutive year of Polaris increasing its dividend.

Summary:
First-quarter North American retail sales were up a robust 70%, continuing the unprecedented levels of growth.
We continue to see an expanding customer base, with new customers growing 70% in Q1.
Both Indian and Slingshot's first-quarter retail was strong as well, collectively finishing up over 70% and market share increased about 3 percentage points.
First-quarter sales were up 39% on a GAAP and adjusted basis versus the prior year.
First-quarter earnings per share on a GAAP basis was $2.11.
Adjusted earnings per share was $2.30, which was up significantly over last year's first quarter.
Moving on to our revised guidance for 2021.
Given the stronger-than-anticipated performance in the first quarter, we have increased our total company sales growth guidance and now expect sales to increase in the 18% to 21% range for the year, up from the 13% to 16% we guided in January.
We are also increasing our full-year adjusted earnings per share guidance for 2021 and now expect earnings to be in the range of $9 to $9.25 per diluted share.