LOS ANGELES (AFP) — Rising amateur star Nick Dunlap withdrew from this week's PGA Tour event at Torrey Pines in California on Monday, saying he needs time to mull his future following his breakthrough professional victory at the weekend.

Dunlap became the first amateur to win a PGA Tour event since 1991 on Sunday when he clinched the American Express tournament in La Quinta, California.

The 20-year-old University of Alabama student said after the win he was uncertain if he would continue his amateur career or immediately jump to the PGA Tour.

In a statement on Monday, Dunlap said he was withdrawing from this week's PGA Tour event outside San Diego to reflect on his options.

"After a life-changing last 24 hours, I've decided to withdraw from the Farmers Insurance Open," Dunlap said Monday.

"I plan to return home to Alabama to be with family, friends and teammates. Thank you to Farmers Insurance and American Express for giving me these opportunities."

Asked on Sunday about the possibility of turning professional following his one-shot win at the American Express, Dunlap said he was undecided.

"I don't know," Dunlap said.

"I have to take a second to let what just happened sink in a little bit. That's a decision that's not just about me."

"It affects a lot of people, and obviously I'm going to try to enjoy this. It's a conversation I need to have with a lot of people before I make that decision."