DETROIT -- Sam Dyson may have been sour in Texas, but has sweetened up the San Francisco bullpen.

Dyson mowed down three Detroit hitters in the ninth inning Wednesday night for his third save since joining the Giants from the Rangers, sealing San Francisco's 5-4 victory and pushing the Tigers one step closer to a potential payroll pruning.

Hunter Pence drove in three runs with a groundout and a triple to help the Giants improve to 7-1 over their last eight games. San Francisco (34-52) is 4-1 with one game remaining on its road trip, clinching its first winning trip since the middle of last season.

"This was a great win. We're just getting better all around," San Francisco manager Bruce Bochy said. "(Starting pitcher Ty) Blach did a great job. Hunter swung the bat well.

"Dyson has made a good contribution. He throws strikes. It was a great move for us. He's been a big help."

Bochy eased Dyson back into a closer role, which he may have to relinquish when Mark Melancon returns from the disabled list.

Detroit rallied for four runs in the seventh, but Cory Gearrin, the last of four pitchers used in the inning, struck out Justin Upton with two on to end the burst.

"In the seventh inning, I thought we were going to make a full comeback," Tigers manager Brad Ausmus said.

Blach was cruising with a three-hit shutout through six innings but gave up three consecutive hits and exited without retiring a batter in the seventh. Miguel Cabrera singled to center, J.D. Martinez doubled near the line in right, and both scored when Victor Martinez bounced a single up the middle.

Gearrin walked Jose Iglesias with one out and gave up an RBI single to Ian Kinsler that hit the pitcher's leg and ricocheted to third. Nicholas Castellanos hit a sacrifice fly to right to make it 5-4.

"Getting hit by a ball is never fun," Gearrin said. "Whether it turned up the intensity, I don't know, but I wanted to stay out there. I knew it wasn't going to feel good in about 20 minutes. It definitely has tightened up a bit now."

Hunter Strickland pitched the eighth, and Dyson, who was 1-6 with the Rangers, worked a perfect ninth.

Gorkys Hernandez had three hits for San Francisco.

Blach (6-5) walked one and struck out two and was charged with three runs.

Pence drove in his first run in the third, breaking a scoreless tie on a sharp groundout to Daniel Norris (4-7) with runners on second and third and one out. Norris checked the runner and probably would have caught Kelby Tomlinson moving toward the plate but was too quick to throw to first.

Jae-Gyun Hwang then lined a soft RBI single to center with two out to make it 2-0.

Pence tripled home a pair of runs with a line shot to right-center in the fourth after Brandon Belt singled home a run with two outs. Nick Hundley doubled with one out and Tomlinson walked prior to Belt's single up the middle.

Norris lasted four innings, allowing five runs and seven hits with two strikeouts and four walks (two intentional). There has been speculation Detroit would option Norris to Triple-A Toledo during the All-Star break since he wouldn't be starting until the week after the All-Star Game -- and Ausmus sounded as if that might occur.

"Clearly we need better results than that," Ausmus said. "For a number of reasons. It doesn't help us win games, and puts undue stress on the bullpen.

"He does have a bit of a groin issue. We'll have to address that as well.

"At some point we've got to mature and get past it and find a way to calm ourselves in situations that are tough or tight. You've got to be able to get through it. People that succeed at this level as pitchers learn to get through it."

The Tigers (37-46) need to get hot over the final six games prior to the All-Star break to stay out of the seller's pool. J.D. Martinez, Justin Verlander, Justin Wilson and Alex Avila have been the subject of trade rumors over the last few days.

NOTES: RHP Alex Faedo, Detroit's first choice and the 18th overall selection in the June draft, signed a contract worth an estimated $3.5 million. He will report to Detroit's spring training base but won't pitch, having thrown some 130 innings for Florida this year. ... San Francisco LHP Madison Bumgarner (ribs, shoulder) gave up nine runs on nine hits in four innings for Class A San Jose on Wednesday in his third rehab start. ... Giants 3B Conor Gillaspie (back spasms) also made a rehab appearance with San Jose and could be activated Friday, manager Bruce Bochy said. ... OF Alex Presley was activated off the concussion list, with Detroit sending OF Matt den Dekker back to Triple-A Toledo.