Justin Rose, Brooks Koepka in Fort Worth Invitational Final Group

The only things that rivaled the sweltering heat at the Fort Worth Invitational’s third round was the starts by Justin Rose and Jon Rahm and the finish by champion Brooks Koepka.

Rose, the 2013 U.S. Open champion, began the day atop the leaderboard at Colonial Country Club and solidified it with three straight birdies to start and 4-under through the first six holes to put some distance between himself and the field. The only blemish on his card was a bogey on the par-3 16th hole.

“Definitely a great start for me today,” Rose said. ” Two really nice swings at No. 1 and two puts is a simple way to start. Nice little kick-in birdie at No. 2 and then holing a mid-range putt at No.3 was kind of good. It got me feeling good about my putting as well.”

Following his par on the No. 18, Rose finished the third round with a four shot lead.

“Great position going into tomorrow,” Rose said. “Look forward to putting it away, but I kind of know there are going to be challenges out there tomorrow. I’m ready for them either way.”

If Rose holds on for the win Sunday in Fort Worth, he would tie Nick Faldo for the most PGA Tour wins (9) by a player from the country of England.

One of Rose’s biggest challenges on Sunday at Colonial will be in the form of his playing partner Koepka.

Koepka, winner of last year’s U.S. Open, is four-over par for the week on the par-5 11th hole including a double bogey during Saturday’s third round. He did manage to turn things around and followed the 11th up with three birdies in his final seven holes to reach 10-under and ensure himself a spot on the final pairing on Sunday alongside Rose.

“Got to get off to a good start here,” Koepka said. “If you can birdie the first two at least and put some pressure on Rosey, you’ll be just fine … Important thing is we were just trying to get into that final group . I thought that putt on 18 was kind of big to get in that final group and play with Rosey.”

Koepka leads the field in strokes gained off the tee at +4.122.

The biggest mover on “Moving Day” at Colonial was world No. 4 Jon Rahm. Rahm began his day 6-under through 10 and offset a bogey on No. 11 with a birdie on No. 17 to fire a 64.

“That’s probably the best 10 holes I’ve played so far this year,” Rahm said. “It was an amazing performance. Front nine I felt like I didn’t miss a shot and when I got out of position, I was able to fix it and sometimes make the putts.”

NOTES

— Rickie Fowler, playing in his first Colonial since 2014, is in a tie for 21st at 5-under. His five birdies were offset by four bogeys on Saturday.

— Jordan Spieth has a win and two runner-ups in the last years at Colonial, but after an EVEN par round on Saturday, the Dallas native sits in a tie for 38th heading into the final round. Spieth has finished no worse than T14 in five Fort Worth Invitational starts.

— 2014 Colonial champion Adam Scott made the cut on the number and following a 1-over third round, will be in the first group out on Sunday morning.