NEW YORK (AP) – Jorge Posada hit a tying home run in the fifth inning, then added a three-run, upper-deck drive in the sixth that backed starter Mike Mussina in his return from elbow trouble and led the New York Yankees over the Baltimore Orioles 7-6 on Thursday night.

A night after moving past the Boston Red Sox to take over first place in the AL East for the first time since July 18, the Yankees won for the 10th time in 11 games and opened a season-high one-game lead with 10 remaining.

Mussina (13-8) pitched for the first time since Aug. 29, when he left a start at Seattle with elbow inflammation. The right-hander allowed four hits in six innings, struck out six and walked none, throwing 76 pitches. Baltimore’s only run off him came in the third, and it was unearned.

Luis Matos singled leading off, shortstop Derek Jeter allowed David Newhan’s potential double-play grounder to bounce off his glove for an error, and Bernie Castro singled in the run. With two on and no outs, Mussina retired Melvin Mora on a soft liner to Jeter.

Former AL MVP Miguel Tejada followed with a hard drive that Jeter caught with a leap, and the shortstop made a backhand flip to second baseman Robinson Cano for a double play.

Al Leiter gave up run-scoring hits to Tejada and Gibbons in the eighth, and Tanyon Sturtze allowed an RBI grounder to B.J. Surhoff and a run-scoring double to Javy Lopez – runs that were charged to Leiter.

With Mariano Rivera having appeared in three straight games, Tom Gordon pitched the ninth for his second save, He allowed a two-out homer to Mora, then got Tejada to ground out on the next pitch.

Gary Sheffield also homered for the Yankees, reaching 30 for the third straight season and eighth time overall.

Posada has tried to inspire the Yankees for the stretch run, handing out T-shirts to teammates that say “Grind It” on the front and “There is no trying, there is only doing or not doing” on the back.

He led by example as New York completed a four-game sweep of the Orioles, who at 70-82 are assured their eighth straight losing season, the worst stretch for the franchise since the St. Louis Browns/Orioles went 11 in a row from 1946-56.

Bruce Chen (12-10) retired 12 straight batters before Posada led off the fifth with a drive just to the left of straightway center, tying the score 1-1.

Then in the sixth, Tejada allowed Cano’s hard one-hopper to shortstop bounce off him for an error. Sheffield’s single moved Cano to second, and Cano slid home ahead of Jay Gibbons’ throw on Hideki Matsui’s single to right for a 2-1 lead.

Posada followed with a drive about five rows into the left-field upper deck that finished Chen.

Chen, who had allowed two earned runs or fewer in eight of his previous nine starts, gave up five runs – four earned – and five hits in 5 1-3 innings.

Cano tripled off Aaron Rakers leading off the seventh, a drive about 6 inches from the top of the right-field wall, and scored on Alex Rodriguez’s sacrifice fly. Sheffield’s second homer in three games made it 7-1.

Notes: Gibbons went to first base in the fourth, when Mussina bounced a 2-2 pitch that appeared to hit him on the foot. Gibbons went to first, but plate umpire Randy Marsh ruled he swung and struck out. … Posada had his second multihomer game this season and the 11th of his career. He has 19 home runs this season.