SAN FRANCISCO -- For most of the past two months, Zack Wheeler has pitched as well as, if not better than, Jacob deGrom. The Mets are even beginning to offer him similar levels of support.

Walking a razor's edge Friday for the third consecutive start, Wheeler allowed one run in seven innings of a 7-0 loss to the Giants. The Mets have given Wheeler four total runs of support in his last three outings, dropping him on Friday to his first defeat since June 22.

"They've both been going out there every five days and giving us a chance to win," Mets manager Mickey Callaway said of Wheeler and deGrom. "And we haven't always capitalized on that."

Dominant throughout the game's first six innings, Wheeler retired six consecutive batters at one early juncture and seven in a row at another, guiding the Mets into a scoreless tie in the seventh. Brandon Belt led off that inning with a double down the right-field line, moved to third base on Austin Slater's groundout and scored on Chris Shaw's sacrifice fly.

It may not have been much, but it was enough to topple Wheeler, who entered the night 7-0 with a 1.88 ERA in his previous 11 starts. Since the All-Star break, Pittsburgh's Trevor Williams is the only qualified pitcher in the Majors with a better ERA than Wheeler's 1.19 mark.

"That's the plan every time. It's just been happening," Wheeler said. "I've been able to go out there and really get it done. I'm happy about it and I'm going in the right direction."

The Mets' offense, however, is not. After Jeff McNeil doubled off Giants starter Andrew Suarez in the first inning, the Mets did not put another runner on base until McNeil was hit by a pitch to lead off the seventh. Suarez completed seven innings, and the Giants eliminated any remaining drama with a six-run rally off Robert Gsellman, Daniel Zamora and Drew Smith in the eighth.

MOMENTS THAT MATTERED

Sick (by the) bay: Pitching for the first time in a week, Gsellman, who lost several pounds due to a recent bout of strep throat, could not record an out in the eighth. Aramis Garcia led off the inning with a homer off Gsellman, who also served up a Gregor Blanco double off the right-field wall before departing.

Zamora entered and, after striking out the first two batters he faced, walked Evan Longoria and allowed Belt's two-run triple. Then Smith allowed all four batters he faced to reach base, turning a close game into a blowout.

"They're just throwing balls down the middle, and a tad up," Callaway said of his bullpen. "They all have really good stuff and they're still learning to use it well. When you make mistakes, big league hitters make you pay, and we've been making a lot of mistakes lately."

SOUND SMART

Finishing 3-for-29 against Suarez and a pair of left-handed relievers, the Mets dropped their season average against lefties to .224 -- the lowest mark in the National League, and second-lowest in the Majors.

"It's kind of been that way all year," Callaway said. "It's something we definitely need to address."

HE SAID IT

"I think it's just consistency mechanically, just trusting my stuff and going right after guys. It's staying in the game and being healthy, for the most part." -- Wheeler, on his run of success

FROM THE TRAINER'S ROOM

Mets shortstop Amed Rosario was out of the starting lineup after undergoing an emergency root canal earlier in the day. The team expects him to be available Saturday.

SEPTEMBER CALLUPS

The Mets announced that relievers Eric Hanhold and Tim Peterson will join the team Saturday, when rosters expand. Peterson spent time with the Mets earlier this season but Hanhold, whom the team acquired in the Neil Walker trade last August, will be making his big league debut.

The Mets will wait until the Minor League season ends before making additional callups, including first baseman Dominic Smith.

UP NEXT

The Mets hope Steven Matz turned a corner last time out, when he delivered arguably his best start of the season in a loss to the Nationals. They'll find out Saturday, when Matz returns to the mound for a 4:05 p.m. ET game at AT&T Park. Left-hander Derek Holland is scheduled to start for the Giants.