San Diego, CA (SportsNetwork.com) - Buster Posey smacked a two-run homer in the first inning and the San Francisco Giants held off the San Diego Padres, 4-3, in the finale of a three-game set.

Angel Pagan had a two-run single in the following frame for San Francisco, which halted a three-game losing streak.

Tim Lincecum (1-1) struck out seven and allowed three runs on seven hits and three walks over six frames to notch the win. Sergio Romo fired a scoreless ninth to pick up his fifth save of the season.

Nick Hundley cracked a solo shot among his two hits for the Padres, who had won five of their last seven tilts coming in. Robbie Erlin (1-2) surrendered four runs on three hits and three walks over six frames in the loss.

The Giants plated a pair of runs in the first and second to jump out to a 4-0 lead.

Hunter Pence worked a one-out walk in the first before Posey launched a towering shot into the San Francisco bullpen in left-center field.

San Francisco loaded the bases with one away when Brandon Hicks walked, Brandon Crawford singled and Lincecum was issued a free pass. Pagan then plated Hicks and Crawford with a base hit into right-center.

San Diego got two runs back in the third on Chase Headley's two-run double, and Hundley's leadoff blast to left in the seventh trimmed the deficit to 4-3.

The Padres, though, never threatened over the final two innings.