"We're just playing baseball the way we wanted to play it from the beginning," said Mussina (11-10). "We had a lot of struggles in the beginning of the season, and now, with a week to go, we're in the position we want to be in. We're playing the game the way we want to play it. It's not anywhere close to the same team it was in April and May."
The Yankees have won 14 of 17 to improve to a season-high 25 games over .500. New York will complete its home schedule on Monday, making up an April 25 rainout, before playing its final six games on the road.
"This is the time of year that you want to play well, because the pressure is on," Yankees manager Joe Torre said. "You have certain things that you need to accomplish. We've played well under pressure all year. The most important thing is to make sure we don't lose our edge."
Mussina, who had to be pulled from the rotation in late August after three consecutive horrid starts, has re-emerged in September to regain Torre's trust. With the exception of a three-run blip in the second inning, Mussina held Toronto scoreless in six of the seven innings he pitched on Sunday, including retiring nine straight to close out his start.
"I'm just glad [Torre] gave me a chance to go back out there and pitch," Mussina said. "He didn't have to. He made a decision and could have stuck with it. They let me get back out there and do it again, and I've thrown the ball pretty well since they let me back out there. It's the way the game works sometimes."
Mussina scattered seven hits and struck out five to move past Vic Willis for sole possession of 43rd place on baseball's all-time wins list, one shy of longtime Torre favorite Bob Gibson.
"It's nice to have been given a chance to go out there for that long a period of time, a chance to win 250 games," Mussina said. "To play with some of the talent and some of the people that I've had a chance to do it, it's been a lot of fun. It's been great, and I hope to go out there and win a few more."
After playing two extra-inning contests to open their series with the Blue Jays -- 25 innings of baseball that spanned nine hours and 45 minutes -- the Yankees were able to record Sunday's win in more efficient fashion.
Toronto starter Dustin McGowan was chased in the fifth inning, as Robinson Cano gave New York the lead on the final pitch from McGowan (11-10), ripping a run-scoring single to right. Facing reliever Brian Tallet, Doug Mientkiewicz nubbed a slow roller up the third-base line that Russ Adams could not barehand, allowing a second run to score on the hit.
Jose Molina then came through with a bloop single to left that brought home New York's sixth run, one of a season-high three RBIs in the backup catcher's three-hit game.
Molina opened the season with the Angels, now a possible playoff opponent, and has provided an upgrade over original backup Wil Nieves. After Jorge Posada caught all 10 innings of Saturday's arduous five-hour affair, Molina was able to offer a full day off and yet not hurt the team offensively -- he has hit safely in nine of his last 10 starts and 10 of 14 since joining the Yankees.
"I'm still adjusting," Molina said. "It's not easy. I've been on the West Coast for seven years, and coming to the East Coast, it's not easy, family-wise or personal-wise. You've just got to step up and do your job, no matter what the situation is. When you get home, you deal with those things."
The two clubs traded three-run innings in the second, as Mussina saw a string of 14 scoreless frames end. Adam Lind had a two-run double and Curtis Thigpen had a run-scoring single for the Blue Jays, but the Yankees answered with run-scoring singles by Molina, Johnny Damon and Derek Jeter in the bottom half, providing Mussina with enough of a cushion to get back to work comfortably.
"He was great," Molina said. "He was hitting his spots. In the second inning, he gave up some runs, but those pitches were good. There wasn't anything bad at all."
Mussina also had strong defense and some fortunate play-calling. Molina picked off Alex Rios on a snap throw down to first base in the third inning, and Melky Cabrera, who preserved a tie game in the 10th inning on Saturday with an outfield assist, turned in another on Sunday to throw out Gregg Zaun at the plate on a questionable tag play ending the fourth inning.
Like on Saturday, the Yankees had to endure a bullpen crisis, but this time they had a magic answer. Before the game, Torre had indicated to reporters that rookie sensation Joba Chamberlain would be unavailable, but he reversed field after consulting with general manager Brian Cashman and pitching coordinator Nardi Contreras, the architect of the so-called "Joba Rules."
"We're on the move with this thing," Torre said. "A lot of it is going to be judged on pitch counts. The days off will vary. Certain situations have to be right for us to be in a position to use him, and unfortunately, it called for that."
Reliever Luis Vizcaino surrendered a two-run homer to Matt Stairs in the eighth, but Chamberlain -- pitching on his 22nd birthday -- was summoned to pitch out of a two-out, two-on jam, striking out Lind on a slider to end his inning. Since Chamberlain threw just five pitches to Lind in the eighth, the Yankees sent him back out for the ninth, when he set the Blue Jays down in order for his first career save.
"It's all fun," Chamberlain said. "It's all new experiences every time I go out there, so it's good."