Shares of

AutoZone

(AZO) - Get Report

drove higher Tuesday after the auto parts seller posted a big earnings beat, with buybacks helping to boost per-share results.

AutoZone's earned $213.5 million in its fiscal fourth quarter, up 3.3% from $206.6 million a year earlier. On a per-share basis, earnings jumped 9.6% to $2.92 from last year's $2.66. Analysts, on average, had expected earnings of $2.79 a share for the quarter ended Aug. 26, according to Thomson First Call.

AutoZone's aggressive share repurchasing has consistently boosted its earnings per share. The retailer bought back 3.7 million shares of its common stock for $340 million in the quarter, at an average price of $91 per share. The company averaged 73.1 million shares outstanding during the quarter.

For its fiscal year ended August 26, AutoZone repurchased 6.2 million shares for $578.1 million, at an average price of $93 a share.

The buybacks helped increase EPS amid a same-store sales decline. AutoZone's total sales for the quarter rose 3% to $1.9 billion, but its same-store sales, or sales at stores open for at least a year, dropped 0.9%. That decline is indicative of the competitive pressures facing the company as its customers struggle under the weight of high gas prices.

"While we are pleased with this past quarter's bottom-line results, and we are encouraged with the progress we are making on the major initiatives launched at the beginning of the year, we were not satisfied with this quarter's sales performance," said AutoZone in a press release.

"Our ongoing initiatives, which focus on improving the customer shopping experience, resulted in measurable increases in customer service metrics throughout the year. While the financial burdens faced by our customers have been well-documented by many retailers, we continue to believe there are many opportunities to further improve our sales performance for the future."

Shares of AutoZone recently were up $4.38, or 4.7%, to $98.48.