ST. PETERSBURG, Fla. -- For Tampa Bay's Jeff Niemann, beating the New York Yankees for his 13th victory was a perfect ending to what the Rays believe has been a rookie of the year season for the big right-hander.
"I think he's a very strong candidate. Actually I think he is the candidate," manager Joe Maddon said Saturday night. "I think he should win it."
Slumping Dioner Navarro hit a two-run homer and the 6-foot-9 Niemann (13-6) pitched five solid innings to beat Andy Pettitte 5-3 for his first win in more than a month.
Victory No. 13 came in his seventh try, although he left four of his six previous starts with a lead or the score tied.
"He's pitched well enough to have more wins than that," Maddon said. "We just have not played the complete game all the time behind him, particularly offensively."
Navarro, who has just four hits in his last 33 at-bats, homered off Pettitte (14-8). Niemann allowed two runs and six hits while taking over the lead in innings pitched by an AL rookie this season.
"It's been a great year all around. To even be considered [for rookie of the year] is an honor itself," Niemann said. "I put a pretty good case together. We'll just see how it goes."
With virtually nothing to play for on the final weekend of the regular season, the AL East champion Yankees have dropped the first two games of this series with their top two starters pitching poorly.
The Rays beat 19-game winner CC Sabathia on Friday night and will go for a sweep Sunday against A.J. Burnett.
"I'm sure guys are looking forward to next week," Yankees manager Joe Girardi said. "You try not to. We've talked about playing good baseball, and we have not done it here."
Still, Girardi is more concerned with making sure the team is ready for the postseason.
In addition to giving Derek Jeter and Alex Rodriguez Saturday off, he announced before the game that right-hander Joba Chamberlain likely will work in relief Sunday and could be headed to the bullpen for the first round of the playoffs.
Girardi said Chamberlain, 9-6 with a 4.78 ERA in 31 starts, will pitch an inning or face a couple batters in the finale against the Rays.
With New York likely to only need three starters for the divisional playoff round, Chamberlain is open to the idea of working out of the bullpen. He made his big league-debut in 2007 as the setup man for closer Mariano Rivera, then worked part of 2008 as a reliever before joining the rotation.
"It's not something new, so I have a plan on what I need to do to get ready because I've done it before," Chamberlain said. "That's the advantage that I have. Just come to the ballpark, have the idea you're probably going to pitch in a game and go from there."
The Rays scored three runs off Pettitte in the second on Navarro's eighth homer and Jason Bartlett's RBI single. They added two unearned runs off the Yankees starter without getting a hit in the fifth.
"It was ugly. ... There's not one thing I can take out of it that was positive," said Pettitte, who allowed five runs, six hits and four walks in 4 1/3 innings. "It's tough, but you still have pride and want to go out and pitch a good game."
Pettitte departed after walking Ben Zobrist and B.J. Upton with one out in the fifth. Both runners scored before reliever Alfredo Aceves even threw a pitch, racing home on a throwing error charged to Aceves.
With Aceves about to go into a stretch, the runners took off on an attempted double steal. Aceves stepped off the rubber and threw to third in plenty of time to get Zobrist, however the ball glanced off third baseman Eric Hinske's glove and skipped up the left field line in foul territory.
The Yankees scored twice off Niemann in the fifth on RBI singles by Johnny Damon and Mark Teixeira. Jerry Hairston, Jr.'s run-scoring single off Lance Cormier trimmed New York's deficit to 5-3 in the sixth.
Niemann, who hadn't won since Aug. 24, walked one and struck out five. Cormier, Randy Choate and Grant Balfour, who earned his fourth save, limited the Yankees to one run over the last four innings.
Teixeira, hit on the left hand by a pitch Friday night, went 1 for 3 and remained tied with Tampa Bay's Carlos Pena for the AL lead in home runs with 39. ... When Upton hit for the cycle by the fifth inning of Tampa Bay's 13-4 win Friday night, he became the first AL player to do it that early in a game since 1954. ... Niemann and fellow Rays rookie starters David Price and Wade Davis are a combined 25-14. Davis (2-1) faces the Yankees on Sunday.