SAN FRANCISCO -- Thirty-five-year-old Marlon Byrd has found the Fountain of Youth: batting behind 30-year-old teammate David Wright.
Byrd belted Jake Dunning's first pitch for his seventh career grand slam, capping a five-run eighth inning that vaulted the New York Mets to a 10-6 victory over the tail-spinning San Francisco Giants on Tuesday night.
The win, on the heels of the Mets' 4-3, 16-inning triumph Monday, allowed New York to improve its road record to 22-21, third best in the National League. The Mets have won 12 of their past 17 road games and 15 of 24 games overall.
The difference was Byrd's blast, his first grand slam since 2009. It increased his RBI total to 47, six shy of his combined total with the Chicago Cubs and Boston Red Sox the past two seasons.
"Baseball's fun," the first-year Met said. "You don't always come through, but when you do, you feel good."
One-out singles by Omar Quintanilla off Jose Mijares (0-2) and by pinch hitter Juan Lagares off Jeremy Affeldt got the New York eighth going in a 5-5 game. Quintanilla's hit was his third of the game.
Eric Young Jr. drew a walk to load the bases, and Daniel Murphy put the visitors on top for good with a sacrifice fly to center field.
After Wright walked to load the bases again, Byrd greeted the right-handed Dunning with a towering drive into the left field bleachers. It was his 14th homer of the season.
"I knew they weren't going to pitch to David," Byrd said of Wright, who drew two walks after having three the night before. "You've got to come through."
While many in the sellout crowd had left the ballpark the night before late in the 5-hour, 26-minute marathon, Byrd was paying attention when the Giants brought in the rookie Dunning from the bullpen.
"I saw him (Monday) night. He has a nice slider," Byrd said. "I saw it pop out of his hand, and I put a good swing on it."
Byrd's RBI total is four higher than that of Wright, a National League All-Star.
"He's been a huge, huge force in the middle of the lineup," Mets manager Terry Collins said of Byrd. "We needed someone to hit behind David. They were walking him and walking him. We needed someone to pick us up."
Mets left-hander Scott Rice (4-5), who faced one batter in the seventh inning and preserved a 5-5 tie, got the win.
The loss was the Giants' seventh in their last eight games and dropped the defending World Series champs into a last-place tie with the San Diego Padres in the National League West. San Francisco is 17-34 in its last 51 games, the worst record in the majors over that stretch.
The Giants scored their final run with two outs in the bottom of the ninth on pinch hitter Nick Noonan's RBI single off Carlos Torres, who pitched the final two innings for the Mets. Noonan had been hitless in his previous 22 pinch-hit at-bats.
Even though San Francisco wasted many of its 13 hits by stranding 11 baserunners, starting pitcher Barry Zito couldn't blame the offense for this defeat.
"This was a lot different than last night," he said. "All those runs we got (Tuesday). My job is to hold them down. I didn't do that."
Zito was pulled after the sixth inning, having given up five runs on seven hits and four walks. He struck out five.
Mets starter Dillon Gee, who hadn't allowed more than two runs in six of his previous seven starts, staggered through 6 2/3 innings before, like Zito, leaving with a no-decision. The five runs he allowed were the product of nine hits and a season-high five walks. He struck out three.
Giants left fielder Kensuke Tanaka had a memorable major league debut. He reached over the fence to rob Andrew Brown of a home run in the second inning, and three innings later recorded his first big-league hit, a single to center field. He went 1-for-4 with a walk.
NOTES: Wright had a double and a single to go with his two walks, running his hitting streak to 10 games. ... Tanaka, a 32-year-old who was hitting .330 in 78 games at Triple-A Fresno, was the sixth man to play left field for the Giants this season, following Gregor Blanco, Andres Torres, Francisco Peguero, Brett Pill and Cole Gillespie. ... Gillespie, 0-for-7 for the Giants this season, was designated for assignment to make room for Tanaka on the active roster. ... The Giants signed OF Jeff Francoeur, who had been designed for assignment by the Kansas City Royals, to a minor league contract and sent him to Fresno. Francoeur, a nine-year major league veteran, hit .208 in 193 plate appearances for the Royals this season. ... The Giants also placed C Hector Sanchez (strained right shoulder) on the disabled list and recalled LHP Mike Kickham from Fresno. ... Mets RHP Shaun Marcum will have surgery designed to cure numbness in his pitching hand next Monday and will be lost for the season. Marcum, 1-10 with a 5.29 ERA in 14 appearances (12 starts) this season, will be replaced in the rotation by Torres once the Mets return to a five-man rotation after the All-Star break. ... RHP Gonzalez Germen was summoned from Triple-A Las Vegas to take Marcum's spot on the roster.