If you ever play a round of golf with Phil Mickelson, make sure you stuff a few hundreds in your pocket beforehand.

Just ask Webb Simpson.

Simpson got a taste of Mickelson‘s gambling habits during the 2011 Presidents Cup. He didn’t exactly want to put up any money during a friendly practice round against the future Hall of Famer and ultra-competitor, but he was quickly reminded that he didn’t have a choice. Simpson recently told the hilarious story about his first and only time betting with Mickelson, and it’s classic Phil.

Phil Mickelson is an avid gambler on the golf course

Mickelson has earned a historic $92.5 million on the course during his PGA Tour career, which puts him second on the all-time list behind only Tiger Woods. But when he isn’t winning money on Tour, he’s betting it during friendly rounds with his buddies or practice rounds before events.

The Mickelson gambling archives are rich with tales of competition, trickery, and high stakes. From betting a patron at Augusta National that he could get an impossible chip up and down for par to predicting Keegan Bradley’s collapse during a money match, Lefty has endless gambling stories he can tell from his nearly 30 years on Tour.

Earlier this week, Simpson, a fellow PGA Tour veteran, told the amusing story about his first time betting against Mickelson.

Webb Simpson learned you don’t have a choice when Mickelson wants to play for money

Unlike Mickelson, Simpson isn’t a huge gambler on the course. He’s earned more than $42 million in winnings during his lengthy PGA Tour career, but he prefers to keep that cash in his wallet.

But when Mickelson wanted to bet Simpson a grand during a practice round in 2011, he quickly learned that you can’t say no to Phil when it comes to gambling.

Simpson told the story on the most recent episode of GOLF’s Subpar podcast with former PGA Tour pro Colt Knost and Drew Stoltz.

“So my first Presidents Cup in Australia, I’m playing in a practice round with Phil and [Jim] Furyk, and on the way to the tee — Bubba [Watson] had played the Ryder Cup in Wales in 2010 — and Bubba said, ‘Just to let you know, we’re probably going to be playing for $1,000 today.’ I’m like, ‘What do you mean? What if I don’t want to?’ And he’s like, ‘Well, you are playing with Phil, you don’t have a choice. I’m just letting you know.’ He’s like, ‘I don’t want to play for that, but that’s what we’re playing for.’

“So we did.”

Simpson bested Mickelson in the $1,000 match

Simpson may not have wanted to throw down four figures on a friendly practice round with his own Presidents Cup teammates, but it wound up being worth the risk.

“Bubba and I won, and I said, ‘Hey Bubba, Jim can pay you. I want Phil to pay me,'” Simpson said. “So I can always say I’m a thousand up on Phil. Never gonna bet him again.”

Oh, and the U.S. went on to beat the International team 19-15. Maybe a little gambling was exactly what they needed to take their competitiveness to the next level.