NEW YORK— A.J. Burnett won his fourth straight decision and Nick Swisher had a big day with his bat and glove, leading the New York Yankees over the Baltimore Orioles 6-4 on Wednesday for their sixth consecutive victory.

Jorge Posada homered and drove in two runs, Alex Rodriguez had an RBI single and Mariano Rivera earned his fifth save in six days. The AL East leaders scored four times in the first inning and sent rookie Jason Berken (1-8) to his eighth loss in a row.
Swisher capped the early outburst with a two-run single and made three fine plays in right field, making up for a third-inning error. Baltimore botched a key defensive play, when second baseman Brian Roberts mishandled Robinson Cano’s RBI infield single with two outs in the first.
Adam Jones, the Orioles’ lone All-Star this season, homered and had four hits. He and Nick Markakis hit consecutive solo shots with two outs in the ninth off Brian Bruney, prompting manager Joe Girardi to call on Rivera.
The 39-year-old closer threw a called third strike past Aubrey Huff to convert his 24th consecutive save and 28th in 29 chances this season.
The Yankees (57-37) woke up alone in first place Wednesday, the first time that’s happened this late in a season since they won the division in 2006.
They played as though they plan to stay there.
Derek Jeter got New York started with a leadoff double, and Posada’s RBI double in the eighth made it 6-2. It appeared the four-run cushion would provide Rivera with a well-deserved rest, but Bruney couldn’t close it out after fanning his first two hitters.
Burnett (9-4) allowed two runs and six hits in seven innings, improving to 9-1 in 11 career starts against Baltimore. The right-hander, who struck out six and walked three, is 4-0 in his past five outings overall.
Phil Hughes, emerging as a reliable setup man, worked a scoreless eighth that included a strikeout and a double-play grounder.
The Yankees are 6-0 since the All-Star break — they opened 8-0 in the second half last year. New York has won 19 of 26 to move 20 games over .500 for the first time since ending the 2007 regular season 94-68.
Next, the Yankees conclude a 10-game homestand with four against last-place Oakland.
Baltimore stranded seven runners through the first four innings and lost its 10th straight game in the Bronx. The Orioles dropped to 1-14 in road games against division opponents this year and 2-25 dating to last season.
Baltimore is 15-32 away from home overall and 1-5 on a nine-game trip to open the second half.
Burnett took a four-hit shutout into the seventh, but Jones’ double put runners at second and third. Markakis hit a sacrifice fly and another run scored on a wild pitch that allowed Huff to reach safely on a strikeout.
Making his first start against the Yankees, Berken fell to 0-8 in 10 starts since beating Toronto 7-2 in his major league debut May 26.
Swisher missed Roberts’ fly ball for a two-base error to start the third. With runners at second and third, Burnett struck out Huff before Swisher ran down Ty Wigginton’s drive into the right-field corner.
Swisher ran up the wall after making the grab and Burnett pointed out toward him with both hands. Swisher also held Luke Scott to a second-inning single on a shot off the wall and mini-jumped at the fence to catch Scott’s drive in the sixth.
NOTES: Orioles manager Dave Trembley said he’ll probably speak Friday in Boston with president of baseball operations Andy MacPhail before deciding whether to remove struggling LHP Rich Hill from the rotation. ... Baltimore dropped to 9-18 in day games. ... RHP Cla Meredith, acquired Sunday in a trade with San Diego, pitched a scoreless seventh in his Orioles debut. ... New York’s series opener Thursday night against Oakland is a makeup of an April 20 rainout. ... The Yankees improved to 32-16 in their new home — 26-9 since Rodriguez returned from hip surgery. ... Burnett also beat Baltimore in his Yankees debut April 9.