They inched closer to the second-place Red Sox in the AL East after Boston started the day a percentage point behind Tampa Bay.
The only run scored in the third inning when Jason Giambi took advantage of an infield shift and hit a tapper to the spot vacated by shortstop Jed Lowrie, who was playing to the right of second base. By the time Lowrie raced back to retrieve it, Bobby Abreu, who had singled and advanced to third on Alex Rodriguez's single, scored easily.
Giambi reached on the single off Josh Beckett (9-7).
Chamberlain (3-3) made his 10th start since moving out of the bullpen on June 3. He had held a team scoreless just once before, on June 25 when he allowed six hits in 6 2-3 innings of a 10-0 win at Pittsburgh.
On Friday, he walked one, didn't allow a runner past second base and retired his last 10 batters, five on strikeouts, as the Yankees moved a season-high 12 games above .500.
Kyle Farnsworth put runners at first and second with one out in the eighth on singles by Lowrie and Coco Crisp. Then Rivera came in, struck out Jacoby Ellsbury and retired Dustin Pedroia on a grounder to the mound. He allowed a one-out single to Kevin Youkilis in the ninth, then struck out the last two batters for his 26th save in 26 opportunities.
Chamberlain gave up singles to Pedroia in the first and Mike Lowell in the second. In the fourth, David Ortiz, returning after missing 45 games with an injured left wrist, singled when his grounder took a bad hop and eluded second baseman Robinson Cano.
Lowell then walked with two outs, but J.D. Drew struck out.
The Red Sox played without one of their hottest hitters when Manny Ramirez was scratched from the lineup with a sore right knee and missed his second straight game. He is hitting .487 during his current 11-game hitting streak.
Chamberlain started the seventh with two balls to Youkilis, the second a high and inside pitch that sent Youkilis to the ground as the ball ricocheted off his bat. Plate umpire Marty Foster warned both benches after Chamberlain's latest pitch that nearly hit Youkilis. Then Chamberlain struck him out.
In Boston's 5-4 loss at New York on July 7, Youkilis scored on a wild pitch on which he slid into Chamberlain, who was covering home. One inning later, the sixth, Youkilis stared at Chamberlain after a pitch behind his thigh. Chamberlain also was suspended for two games last August for throwing consecutive 98-99 mph pitches over Youkilis' head.
