Eddie Pepperell revealed he was playing hungover after charging up the leaderboard on the final day of The Open at Carnoustie.
The 27-year-old Englishman carded five birdies in a four-under-par 67 that lifted him to five under for the championship.
It was a contrast to Saturday when Pepperell felt he squandered some good opportunities as he followed up opening rounds of 71 and 70 with another 71.
He said: "I was a little hungover. I had too much to drink last night. I was so frustrated with yesterday that today was - I wouldn't say a write-off, but I didn't feel as though I was in the tournament.
"I just had some wine with my coach. We drowned our sorrows for about half an hour. It was enjoyable. I didn't really think I had that much to drink. I'm just a lightweight!"
Pepperell admits his approach to this week's tournament, which did not involve a practice round, was "very, very casual".
He said: "I wouldn't always have a drink the night before, sometimes I have a few.
"It depends how you feel. I've done it all different ways. It depends on how you feel. I like to socialise in the evenings if I can. It takes some of the sting out of competitive golf at this level. It's stressful."
Of his final round, Pepperell said: "It was tough, hard work. Just getting the ball to the hole felt hard.
"I managed my game exceptionally well today. I knew on certain tees I wasn't going to hit good tee shots, so I played for the rough and missing bunkers. This course lends itself to that in those conditions.
"Had this course been wet, I wouldn't have had much joy but I managed my game well enough to post a decent score."
