They lost the first two games in their own park.

But the San Francisco Giants completed an improbable comeback today, scoring the first six runs and hanging on for a 6-4 win over the Cincinnati Reds to win their National League Division Series.

Buster Posey's grand slam highlighted a six run sixth inning and gave the Giants a 6-0 lead.

But Cincinnati made it interesting.

The Reds got two of the runs back in their half of the sixth and got to within 6-3 on Ryan Ludwig's seventh inning homer.  But the Reds left two men on in the seventh, eighth and ninth innings.

Ludwig's RBI single in the 9th got the Reds to within 6-4, but Jay Bruce flied out and Scott Rolen struck out to end the game.

It was Rolen's error in the 10th inning of game three that got San Francisco on the board and they made the most of it.

The Giants will now play the winner of the Cardinals-National series in the NLCS.  If St. Louis wins, the series will start in San Francisco.