The Giants had lost three straight home games in the post-season but ended the unwelcome streak in style with a 7-1 thrashing of the St Louis Cardinals.
Marco Scutaro hit a two-run single in San Francisco's four-run fourth inning before leaving the game soon after for X-rays on a hip injury.
That injury came about when Matt Holliday crashed into Scutaro at second base to break up a potential double play in the first inning.
However, Scutaro had the last laugh when his scoring hit in the fourth inning was also mishandled by Holliday in left field.
The series now shifts to St Louis for three games, starting with Game Three on Wednesday.