"There's a lot of emotions, but at the same time, you have to control that," Rivera said. "You have to be able to do that, because you still have to finish the game. It was wonderful."
Making his first appearance since last year's season-ending right knee injury, Rivera permitted a run in the ninth inning but froze Boston rookie Jackie Bradley Jr. with a beautiful cutter on the outside corner to end the game.
The contest marked Rivera's all-time record 609th career save and the 69th save that he has notched in a Pettitte victory, further extending a big league record for the veteran duo. Their last such game came on July 8, 2010, in Seattle.
"These two have been doing it a long time together," manager Joe Girardi said. "As a fan, I appreciate what these two have done together. I know I've caught both of them, I've managed both of them, but as a fan, it's really kind of neat to see."
Lyle Overbay contributed a two-run single while Brett Gardner and Francisco Cervelli homered to support Pettitte, who proved worthy in what Girardi had called a very important game for the Yankees after two rough season-opening losses.
"It was a good win for us," Pettitte said. "You don't want to get swept your opening series here at home. I was proud of the guys, the way they battled. We got some runs, we got some timely hits and we needed it."
Telling pitching coach Larry Rothschild that he felt a little bit strong pitching on an extra day of rest, Pettitte seemed to have some trouble with his command in the first inning. He permitted two singles and then uncorked a wild pitch, failing to cover home plate as the ball bounced to the backstop.
Cervelli tracked the ball down and said that he "fell asleep a little bit" for a split second. With Shane Victorino attempting to score from second, the Yankees caught a break as Cervelli rushed back to home plate and blocked Victorino with a headfirst dive.
"I saw the ball get through his legs, but I just thought it was a couple of feet behind him, so I'm not thinking I've got to cover," Pettitte said. "Then I'm like, 'Oh my gosh, they're going to score a run here maybe.' Thank goodness he's young and he's quick back there."
An appreciative Pettitte handled the Red Sox from there in an economical outing, inducing three double-play grounders and improving to 18-3 in 27 career starts as a Yankee with the club attempting to avoid a regular season sweep.
"There's nobody I'd rather play defense behind, and I've gotten to play behind some good ones, including Mariano and CC [Sabathia] and all those guys," Gardner said. "Andy Pettitte; he's a lot of fun to watch pitch, especially being in center field and getting to see how he works guys in and out and how his ball is moving.
"Every pitch to him is a battle that he's trying to win. If he's throwing a breaking ball first pitch and he throws a ball, he's mad at himself. That's just how he is. He's a competitor and he did great tonight."
Facing Boston starter Ryan Dempster, Overbay dunked a two-run single into left field in the second inning, giving the Yankees their first lead of the season -- and, in turn, their first lead since Game 5 of the 2012 American League Division Series against the Orioles.
Gardner golfed a low pitch from Dempster into the first row of the right-field seats leading off the third inning for his first homer of the season. Dempster lasted five innings and had words of admiration across the way for Pettitte, who outpitched him on this evening.
"To come back out of retirement and pitch as well as he did last year, he's such a hard worker," Dempster said. "He's a guy you should look up to as a peer, because he does things the right way. He just knows how to pitch."
Cervelli connected for the fourth Yankees run in the seventh, launching a solo blast to left-center off Boston reliever Clayton Mortensen.
That provided extra cushion for Rivera, who entered to the familiar strains of Metallica's "Enter Sandman" and closed out the Red Sox around Will Middlebrooks' run-scoring groundout, giving Bradley a taste of what big league hitters have seen for nearly two decades.
"I guess I really haven't imagined facing it," Bradley said. "You know, it does move."
Except for the velocity of the pitch, it could have been a highlight clipped out of -- well, pick your favorite year from 1996-2010. While Pettitte said that it was great to see Rivera run out of the bullpen gate again, he also insisted there was more to be seen than just the nostalgia.
"It's not about the old times," Pettitte said. "It's about us and these new guys and this team we've got right here, and trying to pull this thing together and win another championship."