Bronx, NY -- (Sports Network) - Jason Giambi's solo home run in the sixth inning proved to be the eventual game-winner as the New York Yankees completed a three-game sweep of the Oakland Athletics with a 2-1 victory.

Giambi's round-tripper meant Andy Pettitte's brilliant outing on the hill was not spoiled. Pettitte (11-7), known as an outstanding second-half pitcher, did nothing but further that designation by throwing eight innings of one-run ball. The lefty gave up just four hits with no walks and nine strikeouts.

Giambi finished 2-for-2 with a pair of walks, while Alex Rodriguez accounted for the other RBI for New York, which has won seven straight at Yankee Stadium.

Justin Duchscherer (10-6) was the hard-luck loser, allowing two runs on six hits and three walks to go with four strikeouts through seven innings. The All-Star has not allowed more than two earned runs in his last 11 starts, the longest streak by an American League pitcher since Roger Clemens completed the feat in 1990.

Ryan Sweeney had two of the A's five hits and knocked in the lone run in the club's season-high fifth straight loss.

"You knew it was going to be tough [going against Duchscherer], but they've all been tough lately," Pettitte said. "You have to make good pitches. More than anything I tried to limit my mistakes and fortunately I was able to do that today."

Derek Jeter got the Yankees going with a one-out, ground-rule double to center in the third. Bobby Abreu's single left runners on the corners for Rodriguez, whose fly to right was deep enough to score Jeter. The A's appealed Jeter leaving the bag too early, but he was ruled safe and the Yanks led 1-0.

Pettitte surrendered just two hits heading into the sixth, but Jack Hannahan got ahold of a full-count offering and roped a ground-rule double to open the frame.

A sac bunt form Mark Ellis moved Hannahan to third, and Sweeney bounced an RBI single in front of Melky Cabrera in center to tie the game.

New York took the lead right back with one swing of the bat in the bottom half. Giambi, who came into the game 5-for-7 with three home runs against Duchscherer, continued to frustrate his former team by turning on an inside pitch and putting it just over the right field wall for his 20th home run of the season.

"Giambi seems like my nemesis," Duchscherer admitted. "No matter what I throw he seems to find a way to beat me. It's just frustrating to lose 2-1 like that."

Pettitte yielded to Mariano Rivera in the ninth. A one-out single by Sweeney preceded a wacky play in the field. Bobby Crosby lofted a routine fly to right, but Abreu lost the ball in the sun and dropped it. His throw to second was well over Jeter's head, but Rodriguez backed up the throw and flipped to second base to still get the force out at second.

Rajai Davis, pinch-running for Crosby, attempted to steal his way into scoring position during the next at-bat, but Jose Molina threw him out to seal the win and Rivera's 24th save of the season.

Game Notes

Pettitte is 109-44 in his career following the All-Star break...The A's have been held to one run or less 27 times this year, three more than their total from the entire 2007 season...Rivera has converted all 24 of his save chances this season...On Monday, the Yankees begin a three-game series with the Minnesota Twins in New York, while Oakland heads to Tampa Bay to begin a three-game set...The Yankees are 42-1 when leading after six innings.