NEW YORK -- Jordany Valdespin began the night on the bench and ended it partying at home plate.
A late-inning substitute, Valdespin hit a grand slam in the 10th as the New York Mets rallied past the Los Angeles Dodgers 7-3 on Wednesday to save early sensation Matt Harvey from his first loss of the season.
"Coming back and winning a game like that, that's huge for us as we move forward," manager Terry Collins said.
Matt Kemp hit his first homer of the year and drove in three runs as Los Angeles grabbed a 3-1 lead against Harvey. The budding Mets ace pitched pretty well, though, and was bailed out when his teammates came back.
Pinch hitter Mike Baxter hustled for a leadoff double when his sinking liner to left glanced off the wrist of a sliding Carl Crawford. Baxter advanced on Ruben Tejada's sacrifice, and League had a chance to get out of it after third baseman Jerry Hairston Jr. crashed into the railing to make a spectacular catch on Daniel Murphy's foul popup.
Wright, however, lined the next pitch to right-center for his first hit of the night.
"Definitely a tough one," League said.
John Buck led off the 10th with a single against Josh Wall (0-1), and Ike Davis walked on four pitches. Both runners moved up on Marlon Byrd's sacrifice, and Lucas Duda was intentionally walked to load the bases.
In the dugout, Harvey was encouraging Valdespin.
"I told him they're going to walk Duda and you're going to win this game," the pitcher said. "He was sitting there nice and loose, then he walked up there and delivered."
With the Dodgers playing five infielders and two shallow outfielders, Valdespin drove a 2-1 pitch to right for his first career slam and game-ending RBI.
"I'm not thinking about the infielders. I want to hit a good pitch," Valdespin said. "I'm ahead, it's time to be aggressive and hit the ball."
Valdespin, who grounded out as a pinch hitter with a chance to tie it in the eighth, tossed his helmet high in the air and hopped on home plate into the arms of excited teammates.
"He gets pumped up for that stuff," Collins said. "He just relishes that big moment during the game."
The Mets said it was the sixth walk-off grand slam in club history and their first since Kevin McReynolds connected on June 25, 1991, against Montreal, according to research by the Elias Sports Bureau.
Bobby Parnell (1-0) worked around a leadoff walk in the 10th.
Kemp's two-run shot off Harvey in the sixth, originally ruled a triple before a replay review, snapped a 1-all tie and ended the slugger's drought of 86 at-bats dating to last season.
Ted Lilly tossed five effective innings in his first start since shoulder surgery, giving the Dodgers' injury-depleted rotation a boost. Los Angeles had won five in a row at Citi Field.
The 37-year-old Lilly allowed one run and struck out seven, wriggling out of two jams in his first big league outing since last May. The two-time All-Star opened 5-1 last season before he was sidelined by a left shoulder injury that required surgery in September.
"First time out, pretty good. Yeah, really good. I thought he was sharp," Dodgers manager Don Mattingly said. "That's what Teddy does right there."
Harvey, who beat Washington phenom Stephen Strasburg on Friday, entered with a 0.93 ERA. He fanned seven in six innings against the Dodgers but failed in his bid to become the first five-game winner in the majors. The Mets said he was the first pitcher since 1900 to win his first four starts in a season while allowing no more than 10 total hits, according to research by the Elias Sports Bureau.
Three days later, Tampa Bay left-hander Matt Moore matched that feat.
Hoping to cash in on Harvey's success, the Mets offered a special ticket promotion that included Harvey T-shirts. A crowd of 24,130 showed up on a windy night in Queens to watch the 24-year-old right-hander make his 15th major league start.
"I don't get caught up in the marketing stuff too much," Collins said before the game. "When you're around this guy, he's not caught up in that, either."
Harvey was cruising until he walked Adrian Gonzalez on a full-count pitch with two outs in the sixth. Kemp drove a 2-0 fastball, clocked at 95 mph, toward the right-field corner where a security guard stationed at the foul pole tried to catch the ball just behind the wall.
The ball caromed off his hands and back onto the field as umpires ruled it in play and Kemp pulled into third base. But the umps went inside for a look at the replay and, after a 2 ½-minute delay, correctly called it a two-run homer that gave Los Angeles a 3-1 lead.
"I didn't have my good fastball, so I knew I would be counting on everybody behind me," Harvey said. "I was pretty happy with my changeup. Looking back, I wish I had used it more."
A sacrifice fly by pinch hitter Justin Turner pulled the Mets to 3-2 in the sixth.
Harvey, a legitimate threat with the bat, doubled off the left-field fence leading off the fifth and scored the tying run when Tejada grounded a single just inside first base to snap an 0-for-18 slump.
One hit later, the Dodgers appeared to have trouble with the bullpen phone in their dugout -- the second time that has happened to a visiting team at Citi Field this season.
Harvey was nicked for a first-inning run on Kemp's RBI groundout. Beginning with that batter, he retired 16 of 17.
To open a roster spot for Lilly, the Dodgers optioned catcher Tim Federowicz to Triple-A Albuquerque. ... New York has three grand slams in 19 games this season. ... Mets LHP Jonathon Niese said he might push his bullpen back a day this week but he'll definitely make his next scheduled start Sunday against Philadelphia. Niese was knocked out of Tuesday night's game by a third-inning comebacker that bruised his lower right leg.