SAN FRANCISCO -- Terry Collins offered an upbeat message to Manny Acosta on the mound in the 10^th inning, after Acosta had walked a pair of batters while trying to protect a two-run lead.

With no one warming in the visitors' bullpen -- Elvin Ramirez was the only reliever unused anyway -- Collins said he told Acosta: “Look, a year ago at this time you were as good a pitcher as there was in this league. Relax. Relax and make some pitches. Make them swing the bat. Hitting is hard.”

Acosta did walk two and surrender a run in the 10th, but ultimately notched his first 2012 save. Brandon Belt flied out to deep center with two runners on base to complete the Mets’ 8-7 win.

Collins had chosen to have Acosta pitch to Belt with runners on the corners and two out, even though reliever Clay Hensley was on deck and Giants manager Bruce Bochy had no position players remaining to pinch hit.

Collins suggested he was aware of Bochy's bind, but he did not want any self-inflicted damage, such as a walk forcing in the winning run. So he resolved not to intentionally walk Belt and load the bases for the pitcher’s spot in the order.

“With what Manny was going through, I just couldn’t load the bases,” Collins said. “If I’m going to get beat, I’m going to get beat by somebody else.”

Acosta holding on gave Josh Edgin his first major league win. Acosta had replaced Pedro Beato on the major league roster last Tuesday.

Edgin inherited a runner on third and a one-run lead from Bobby Parnell in the ninth. He appeared to move closer to escaping the jam when he coaxed a grounder to first base by Nate Schierholtz. But Ike Davis missed the ball and the tying run scored.

The official scorer ruled the play a double, but the Mets plan to appeal to Major League Baseball, and would seem to have a legitimate chance to have the scoring changed to an error on Davis.

Edgin ultimately stranded the bases loaded by striking out Marco Scutaro looking on a full-count offering that was called by plate ump C.B. Bucknor.

“We didn’t make the play, but he got us out of it,” Collins said, alluding to Edgin rallying after Davis’ miss. “I was very, very proud of him. Even when he had the bases loaded, he had to make pitches. He made them. I’m pretty impressed with what I’ve seen so far.”

Edgin chuckled when asked if the final pitch to Scutaro was a cutter. Truth be told, the movement that cut back over the outer half of the plate was unintended.

“It was supposed to be a fastball that cut on me,” he said.

As for the ninth-inning experience, the rookie Edgin added: “You don’t have 30,000 screaming fans at [low-A] Savannah. You know what I mean? But it was similar to it, just the bar was raised a little bit.”