Guerrero's big hit came three pitches after Blue Jays manager John Schneider was ejected for arguing balls and strikes. Home plate umpire Charlie Ramos called the first pitch of Guerrero's at-bat, which appeared to land low and out of the strike zone, a strike. Schneider shouted at Ramos from the dugout and was tossed before coming out and arguing at the plate.
"Just wanted to give him a little bit of a deep breath there," Schneider said with a grin.
With Cavan Biggio - a .181 hitter who pinch-ran for designated hitter Brandon Belt in the eighth - in the on-deck circle and first base open, Mets manager Buck Showalter chose to have closer David Robertson (2-1) pitch to Guerrero, who fell behind 1-2.
"'Robbie got ahead of him, thought he could expand the zone on him a little bit," Showalter said. "We just didn't have much margin for error."
The Blue Jays star then evoked memories of his Hall of Fame father, a noted bad ball hitter, by ripping a low and inside pitch for a double down the left field line.
"Senior-esque," Schneider said.
George Springer, who singled with one out and stole second base, trotted home.
Guerrero, who is hitting .285 with eight homers and 36 RBI this season after hitting .292 with 80 homers and 208 RBI the previous two years, pumped his right fist and slapped his chest twice upon arriving at second base.
"He's been grinding, there's been some really good swings, there's been some hard-hit balls," Schneider said. "And I think that results aside, I think the time of the game that it was for us and what it meant for the outcome of it is going to be big for us."
Guerrero said he received an encouraging message in between the top and the bottom of the ninth from center fielder Kevin Kiermaier, who retrieved Guerrero's hat and glove from the dugout.
"Basically, 'That's how we do it, that's how we respond after a bad call, after the manager gets thrown out,'" Guerrero said through an interpreter. "That's the way to do it. And he loved that I stayed calm throughout that at-bat."
Nate Pearson (2-0) struck out two in a hitless eighth and Erik Swanson worked around a one-out single by Mark Canha in the ninth to earn his first save as the Blue Jays clinched a third straight series win.
Daniel Vogelbach hit an RBI double in the second for the Mets, who lost Friday's series opener 3-0 and have scored 11 runs in the first five games of a homestand that ends Sunday.
"Obviously, we've had trouble scoring runs," Showalter said. "They're pitching well, but we're not swinging the bat very well."
Brandon Nimmo had a pair of singles for New York.
Blue Jays starter José Berríos allowed one run and struck out six in six innings. Mets starter Tylor Megill gave up one run despite allowing five hits and issuing five walks in 5 1/3 innings.
HALL OF FAME DAY
Former players Howard Johnson and Al Leiter and current broadcasters Gary Cohen and Howie Rose were inducted into the Mets Hall of Fame before the game. Longtime media relations executive Jay Horwitz also was honored with a Hall of Fame achievement award.
Johnson ranks third in team history with 202 stolen bases and fourth in both homers (192) and RBI (629). Leiter is sixth in wins (95) and starts (213) and eighth in strikeouts (1,106).
The quintet threw out ceremonial first pitches. Jack Leiter, a Texas Rangers pitching prospect, surprised his father by attending the ceremony and caught Al's pitch.
Chris Bassitt tweeted early Saturday that his wife Jessica was still in labor as the couple awaits the birth of their second child. Bassitt tossed 7 2/3 scoreless innings and earned the win in Friday's 3-0 victory before flying home to Toronto. He was placed on the paternity list Saturday morning.
Blue Jays: To replace Bassitt on the active roster, Toronto recalled RHP Jay Jackson from Triple-A Buffalo. ... INF Santiago Espinal (right hamstring) was scheduled to play his third rehab game Saturday night for Single-A Dunedin.
Mets RHP Kodai Senga (5-3, 3.44 ERA) will make his first big league start on four days' rest when he opposes Blue Jays LHP Yusei Kikuchi (6-2, 4.47 ERA) in Sunday's series finale. Senga gave up one hit over seven scoreless innings in a 2-0 win over the Phillies on Tuesday. Kikuchi matched his victory total from last year that same day by limiting the Brewers to two runs over five innings.