ATLANTA—A two-putt par to win the Tour Championship in a playoff was worth an extra $1.5 million to Camilo Villegas.

A 7-iron to a scary pin on the 71st hole, under more pressure than he has ever faced?

That was invaluable.

Villegas overcame a five-shot deficit with six birdies on his final 11 holes of regulation—the last one after going at a dangerous flag on the 17th—and won the Tour Championship on the first extra hole against Sergio Garcia for his second straight victory.

“Winning is awesome,” Villegas said after closing with a 4-under 66.