Overbay homered with two outs in the 11th inning, and the Yankees rallied late to beat the Tampa Bay Rays 4-3 on Saturday.
"He's a big reason why we are where we're at," said New York manager Joe Girardi of Overbay, who is filling in for the injured Mark Teixeira. "It's a big home run. It's a big win."
Overbay drilled a 1-0 pitch from Josh Lueke (0-2) into the right-field seats to give New York the lead.
"I'd been missing fastballs all day, and it was good just to get on top of one," Overbay said. "Exciting to do that."
Ivan Nova (2-1), who made his first relief appearance after returning from a right triceps injury and being moved from the Yankees' rotation to the bullpen, struck out James Loney and got an inning-ending grounder from Matt Joyce with the bases loaded in the 10th.
"I've got to take advantage of every opportunity," Nova said.
Mariano Rivera pitched a perfect 11th inning for his 18th straight save to start the season. The right-hander tied Dennis Eckersley for fourth place for games pitched with 1,071. He had been tied with Hoyt Wilhelm, who coached Rivera in the minors.
"I think that's why we appreciate him so much because of his consistency year in and year out," Girardi said.
The Yankees scored twice in the ninth against struggling Tampa Bay closer Fernando Rodney to pull even at 3.
Gardner was caught attempting to steal second with Robinson Cano batting.
"When we tied it, you've got to feel good about your chances," Gardner said. "The momentum is on our side, but we're still playing on the road and they've got the last shot at it. Another outstanding pitching performance today, and we were able to steal one."
Rodney is just 9 for 14 in save chances this year after converting 48 of 50 opportunities last season.
"This has been really awkward to watch," Rays manager Joe Maddon said. "He's been within one pitch of almost being perfect this season. Three of the blown saves have come down to the last pitch. I've not lost any patience with it. As long as he doesn't lose confidence in himself, I will not lose confidence in him."
"Amazing," Girardi said. "I heard some people in the stands, say 'There it is.' They thought the game was over. There's so many big things that happened in this game to give us an opportunity to win that game."
Rays starter Matt Moore, looking to start the season 9-0, got a no-decision despite allowing one run and five hits in six innings. In his other start against New York this season, the left-hander gave up one run and two hits over eight innings on April 22 in a 5-1 victory.
Yankees rookie Vidal Nuno allowed two runs and five hits over six-plus innings. The left-hander, making his second start and fourth appearance, has given up three runs in 14 innings overall.
Johnson has driven in 18 runs over his 20 games this month.
The Yankees took a 1-0 lead in the first when Gardner had a leadoff double and scored on a two-out single by Travis Hafner.
Tampa Bay tied it at 1 on Desmond Jennings' two-out RBI double during the fifth.
The Yankees are 2-17 when trailing after eight innings. ... Tampa Bay Buccaneers Pro Bowl defensive tackle Gerald McCoy was scheduled to throw the ceremonial first pitch, but was delayed getting to the ballpark due to a minor vehicle accident in which no one was injured. ... Nix was spiked and cut near the right wrist on a seventh-inning pickoff play. He remained in the game and stole second on the next pitch. ... The Yankees put OF Curtis Granderson on the 15-day disabled list with a broken knuckle on his left pinkie and recalled Boesch from Triple-A Scranton/Wilkes-Barre.