Freddy Sanchez capped a three-run seventh inning with a go-ahead, two-run single to lift the San Francisco Giants to a 5-4 victory over the Washington Nationals on Thursday afternoon.

Sanchez greeted reliever Tyler Walker with the single to left field to score Nate Schierholtz and Andres Torres.

Schierholtz singled in a run earlier in the seventh and moved to third on Torres’ double off loser Sean Burnett (0-2).

Brian Wilson finished a perfect ninth by striking out Adam Dunn to notch his 12th save of the season.

San Francisco’s Aubrey Huff went 3-for-4 and hit a leadoff homer in the fourth.

Dunn and Josh Willingham hit solo homers for Washington, while Willingham also had a seventh-inning sacrifice fly that gave his team a 4-2 lead.

Reliever Santiago Casilla (1-0) got the win for the Giants after starter Barry Zito gave up four runs – three earned – and seven hits in 6 1/3 innings.

Washington starter Craig Stammen gave up three runs – two earned – and five hits in 6 1/3 innings.