Brooks Koepka was unsurprised to see Justin Thomas make U.S. Open history with a stunning nine-under 63 on Saturday.
Thomas, 24, lit up Erin Hills during his third round as nine birdies and an eagle helped him break the record for the lowest score to par in the tournament's history.
Koepka, who is alongside Thomas and Tommy Fleetwood in a tie for second, a shot behind surprise leader Brian Harman, said his fellow American's feat came as no surprise.
"I'm happy for him. That's pretty neat to do it in the U.S. Open," said Koepka.
"He's been playing well. So I'm not surprised."
Koepka's four-under 68 kept him in the hunt to win a first major, having recorded three top-five finishes previously.
But the 27-year-old expects no repeat of Thomas' round with stronger winds forecast for Sunday.
"Obviously if it's going to be blowing 25 [miles per hour], I think it will be tough. I would say you've got to be near the top," Koepka said.
"It would be hard to make a real run with 25 mile per hour winds. But with that being said, he did shoot nine under."
Brian Harman leads alone.-- PGA TOUR (@PGATOUR) June 17, 2017
Sunday at the U.S. Open awaits. pic.twitter.com/IpjypTNbLQ
Fleetwood's rounds - 67, 70 and 68 - have matched Koepka's as the Englishman also eyes a maiden major title.
The 26-year-old, twice a winner on the European Tour, was delighted to be in contention.
"I don't think I could play any different or score any better than I have done. And you can't do anything about what anybody else is doing," Fleetwood said.
"If somebody shoots nine under tomorrow in the top few then I'll have to shoot 10, I guess. But you can't do anything about that stuff. I've just got to keep going.
"This is my first time in contention in a major, so whatever happens I'll be doing my best and seeing how well I can finish.
"That's all you can do. But it will be a pleasure to go out on a Sunday trying to win a major."