(REUTERS) - Rookie Austin Cook sank a 14-foot birdie putt on the final hole to seal a four-stroke victory at the RSM Classic on Sunday (Nov 19) and claim his first PGA Tour title.

The 26-year-old had a final-round three-under par 67 in windy conditions to finish on 21-under 261 at Sea Island, Georgia.

J.J. Spaun shot a 66 to seal the runner-up spot at 17-under 265 with Brian Gay (68) another stroke back.

"Fourth tournament with my Tour card, that's pretty impressive if you ask me," Cook told PGA Tour Radio after his win, which earned him exemptions into the Masters, PGA Championship and Players Championship next year.

Cook, who took a three-stroke lead in the final round, dropped a stroke at the second hole but did not let the pressure get to him and remained sold for the rest of the round, picking up shots at seven and 15 before a pleasing birdie-birdie finish.

"Staying the moment," he said was a big key to winning. "I was able to do that really well until about 17 after that putt."

Starting the day with a lead helped, he added.

"If they gain a couple on me early, it doesn't matter because there is still a lot of golf to play," Cook said.

Spaun had applied the pressure early, going four under for his opening 10 holes, but ran into trouble coming home with bogeys at the 11th and 17th holes.

Cook, on the other hand, finished strong, delivering birdies on three of his final four holes.

The former University of Arkansas golfer gained his first experience on the PGA Tour in 2015 when he played in seven events.

The American had finished inside the top 25 five times prior to RSM, including a tie for sixth at the Barbasol Championship.

He earned his PGA Tour card on the Web.com Tour and began playing in Tour events in October.