AutoZone (AZO) beat the Street on Tuesday by revealing an 11% jump in fiscal first-quarter profits as the No. 1 U.S. auto-parts retailer grew its commercial sales by nearly 23%.

Memphis-based AutoZone said it earned $191.1 million, or $4.68 a share, last quarter, compared with a profit of $172.1 million, or $3.77 a share, a year earlier. Analysts had called for EPS of just $4.44.

Revenue increased 7.4% to $1.92 billion, narrowly topping estimates of $1.89 billion. Same-store sales gained 4.6% domestically, while commercial sales soared 22.6%. Gross margins expanded to 51.1% from 50.7%.

"After three years of impressive financial performance, we are pleased to begin fiscal 2012 with strong quarterly results,” CEO Bill Rhodes said in a statement. We remain focused on our disciplined approach of growing operating earnings while efficiently utilizing our capital.”

AutoZone said its inventory grew by 7.2% due to new stores and investments in parts assortment.

Shares of AutoZone rose 1.45% to $343.90 ahead of Tuesday’s open, putting them on track to add to their 2011 rally of more than 24%.

Follow Matt Egan on Twitter @MattMEgan5