Andy Pettitte won his 200th game as a Yankee Friday night, and it came in the midst of what just might be the finest season in the 38-year-old’s 16-year career. After allowing just two earned runs on four hits and a walk in 7 1/3 innings, Pettitte improved to 8-1 on the season with a 2.46 ERA, keeping him right behind the Rays David Price in the Cy Young hunt. Pettitte has posted an ERA below 3.00 just twice in his career. In 1997, as a 25-year-old, he went 18-7 with a 2.88 ERA, and in 2005 as part of the pennant-winning Astros impressive rotation along with Roger Clemens and Roy Oswalt, he went 17-9 with a 2.39. If Pettitte keeps up his current pace, he’ll go 21-3, that 21st win being the 250th of his career.

It’s difficult to believe that Pettitte will get through the entire season without some sort of lull, but it’s nearly mid-June and Pettitte historically pitches better in the second half of the season than in the first. After 12 starts this season, Pettitte has had just one dud, that coming at home on May 20 against the Rays, when he gave up seven runs (six earned) in five innings thanks in part to three home runs. He has allowed a total of just four home runs in his other 11 starts, none of them coming Friday night.

Pettitte has had just two other non-quality starts. One of them missed by a single run (six innings, four runs against the White Sox on April 30), the other missed by a single inning (five innings, one run against the Orioles his next time out). Those were the two starts during which he reported discomfort in his elbow. His next turn was skipped. He then held the Twins scoreless for six innings on May 15 before suffering that one dud against the Rays his next time out. In his four starts since then, he has pitched a minimum of seven innings and allowed a maximum of two earned runs each time out producing this combined line:

30 IP, 21 H, 8 R, 7 ER, 3 HR, 4 BB, 23 K, 3-0, 2.10 ERA, 0.83 WHIP, 5.75 K/BB

To put it another way, in 12 starts, Pettitte has allowed more than two earned runs just twice, lasted fewer than six innings just once (that on account of his elbow, not his performance), and the Yankees have lost just two of games that he started, one of them by a 3-2 score in extra innings.

As for Friday night’s game, Pettitte locked horns in a pitching duel with former Phillies righty Brett Myers. Both had a bad inning early, then settled down and pitched through the seventh in a swift game that took a season-low two hours and 19 minutes.

Myers ran into trouble in the bottom of the first when with one out Curtis Granderson doubled, Mark Teixeira drew a four-pitch walk, and Robinson Cano dropped a single into right that loaded the bases. Myers then threw his first first-pitch strike to Nick Swisher only to fall behind 3-1, get the count back full, then fail to get a high strike call on a curveball that curved over the top of the strikezone but was caught just above the belt. That forced in the first run of the game and Francisco Cervelli followed by singling up the middle on an 0-2 count to plate two more, giving the Yankees an early 3-0 lead.

Pettitte, who had worked a 1-2-3 first on eight pitches, gave two of those runs back right away on a one-out walk to Hunter Pence, Pettitte’s only free pass of the game, a two-out single by Pedro Feliz that pushed Pence to third, and a subsequent double by light-hitting rookie shortstop Tommy Manzella that plated Pence and Feliz.

Save for an infield single by Pence in the fourth, that was all of the action in the game until the fifth, when Kevin Russo, starting in left for Brett Gardner and his ouchy thumb, did his best Gardner impression by drawing a leadoff walk, stealing second, then scoring with two outs when Mark Teixeira flared a ball into shallow right for an RBI single. That insurance run would prove to be crucial.

Only one other batter reached base prior to the eighth (Jorge Posada, who singled but was erased when Myers stabbed a Cervelli line drive and doubled off Posada at first). With Pettitte still on for the Yankees, Manzella led of the eighth with a single. Humberto Quintero then pinch-hit for Kevin Cash and hit a perfect double-play ball to Cano at second, but Derek Jeter closed his glove too fast when attempting the pivot, dropping Cano’s chest-high throw and turning a two-out, bases empty situation into a none-out, men on first-and-second jam in the eighth inning of a two-run game.

Michael Bourne followed with a bunt to move the runners to second and third, and though Pettitte had given up almost nothing since the second inning and was still a couple of tosses shy of 100 pitches, Joe Girardi came out to replace him with Joba Chamberlain.

Said Girardi after the game, “I just thought it was time to go to Joba. . . . Joba’s been our eighth-inning guy . . . I just thought it was time to make a change.”

I wasn’t so sure, particularly after Chamberlain failed to get any of his sliders close to the strike zone against Jeff Keppinger, who brought the Astros within one with a loooong sac fly to right-center on a 3-1 count that moved Quintero to third. Chamberlain then got ahead of Lance Berkman 0-2 on a pair of perfectly placed mid-90s fastballs on the low outside corner, but two attempts to get Berkman, who wasn’t happy with those strike calls, to chase the fastball off the corner failed on account of lack of subtlety. Berkman then fouled off another heater and Joba broke the slider back out. Berkman checked his swing, but third base umpire Tony Randazzo said he went around, ringing the Big Puma up for a game-saving, inning-ending strikeout. Replays showed that Berkman’s bat got parallel to the front of home plate but no further, and I still think the Yankees caught a break on the call.

After a sharp inning from old pal Mr. Gustavo Chacin, Mariano Rivera wrapped up the Yankees’ 4-3 win.

The Yankees have now gone 10-4 (.714) during this soft portion of their schedule and are now just one game behind the first-place Rays, who lost an ugly one to the cross-state Marlins Friday night, for the best record in baseball. With two games left to play at home against Houston, I think the Yanks can pull out a sweep and possibly take a share of first place, but a split would be perfectly acceptable.

In other news, expect Alex Rodriguez (day-to-day with hip flexor tendonitis, reportedly unrelated to his 2009 hip surgery) to sit out the remainder of the series in order to be ready to face the Phillies on Tuesday, though he could be pressed into pinch-hitting duty if needed. As for Gardner, an MRI on his left thumb showed a Grade 1 sprain, but he’s still expected to take batting practice Saturday and return to game action over the weekend.