BOSTON (AP) - David Ortiz was back. Josh Beckett was pitching for the Red Sox . The Fenway Park crowd was pumped up for the renewal of the rivalry with the Yankees.

None of that bothered Joba Chamberlain .

The right-hander took another big step in his transition from the bullpen to the rotation with his best major league start as surging New York beat Boston 1-0 Friday night for its seventh straight win.

The third-place Yankees pulled within two of Boston and stayed three back of AL East-leading Tampa Bay, which won 5-3 at Kansas City. New York also bolstered its bullpen and lineup, acquiring outfielder Xavier Nady and left-hander Damaso Marte from the Pittsburgh Pirates .

Two people familiar with the deal confirmed the trade on condition of anonymity because physicals were still pending.

For New York, Chamberlain's effort and the added help made it a big night.

''I've had quality starts against everybody,'' Chamberlain said. ''You understand it's going to be a tough game. He (Beckett) is an unbelievable pitcher. He battles and claws.''

So does Chamberlain.

''I was the second-best pitcher today,'' Beckett said, ''and ultimately that gets you a loss most of the time.''

Chamberlain has allowed three runs or less in all 10 starts this year. On Friday, he gave up three singles - one to Ortiz, who missed the previous 45 games with a left wrist injury - and struck out nine in a career-high seven innings.

''He matched Beckett inning for inning,'' Yankees manager Joe Girardi said.

Mariano Rivera shut down a threat in the eighth and finished for his 26th save, helping the Yankees remain undefeated since the All-Star break.

''I thought we were playing well before the break,'' Derek Jeter said. ''We lost two out of three but guys pitched well against us. Now it just seems like our pitching is taking it to another level. It seems like guys are trying to outdo each other.''

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 , playing to the right of second base. By the time Lowrie retrieved the ball, Bobby Abreu , who had singled and advanced to third on Alex Rodriguez 's single, scored easily.

Beckett (9-7) said his location was a little off on the pitch Giambi hit for an infield single.

''But it was actually sufficient enough to get a weak groundball,'' Beckett said. ''It just happened to be in a position where nobody was playing.''

Chamberlain (3-3) 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.

''Dustin's been one of the hottest guys in baseball and not just for a week but for a long time,'' Girardi said. ''It's a very difficult out but it's a huge out.''

Rivera allowed a one-out single to Kevin Youkilis in the ninth, then struck out the last two batters.

Chamberlain gave up singles to Pedroia in the first and Mike Lowell in the second. In the fourth, Ortiz reached on an infield single. Lowell then walked with two outs, but J.D. Drew struck out.

The Red Sox were missing one of their best hitters: 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.

He underwent MRIs on both knees and they ''came back fine,'' Boston manager Terry Francona said.

In the seventh, Chamberlain threw a high, inside pitch that sent Youkilis to the ground as the ball ricocheted off his bat. Plate umpire Marty Foster warned both benches before Chamberlain struck him out.

''It's a 2-0 count and the game's 1-0,'' Chamberlain said. ''You think I want to lose the lead?''

In Boston's 5-4 loss at New York on July 7, Youkilis scored on a wild pitch on which he slid into Chamberlain covering home. One inning later, the sixth, Youkilis stared at Chamberlain after a pitch behind his thigh. Chamberlain was suspended for two games last August for throwing consecutive 98-99 mph pitches over Youkilis' head.

''He has great command until Youk gets in there,'' Francona said.

Notes: New York parted with four minor leaguers in the deal with Pittsburgh. ... Lowell was ejected with one out in the ninth for arguing a third strike that appeared to be inside. ... Golf great Jack Nicklaus and country singer Kenny Chesney threw out ceremonial first pitches. Country singer LeAnn Rimes sang the national anthem. ... Pedroia went 1-for-4, hitting safely for the 26th time in 27 games and ninth straight. ... Yankees RHP Phil Hughes , recovering from a fractured rib, threw batting practice in Tampa on Friday and is scheduled to make his first rehab start in the Gulf Coast League on Monday. Oft-injured RHP Carl Pavano , coming back from elbow ligament replacement surgery, is scheduled to pitch there Tuesday.