San Francisco's Travis Ishikawa is on the ground as he celebrates with his teammates his walk-off homer to defeat the St. Louis Cardinals 6-3 for the National League title Thursday night. (Photo: Christian Petersen/Getty Images)

The San Francisco Giants worked hard to clinch the National League Championship Series on Thursday night against the St. Louis Cardinals.

It was a tie game at 2-2 in in the top of the fourth inning, but two home runs led to a 3-3 tie going into the ninth inning.

The Giants turned a double play to get out of the top of the ninth. In the bottom of the ninth, Travis Ishikawa hit a three-run walk-off homer to end the Major League Baseball game and to deliver San Francisco the pennant.