FARMINGTON — On a low-scoring day at Oakridge Country Club, a couple of guys from Colorado jumped to the top of the Siegfried & Jensen Utah Open leaderboard, while a couple of brothers from Utah are just a stroke behind.

Zen Brown, a 25-year-old from Arvada, and Derek Tolan, a 26-year-old from Denver, led the barrage of low scores as both fired 8-under-par 64s Friday and lead three others by one shot.

Two of those at 65 were the Finau brothers, Tony and Gipper, who are joined by St. George pro Dusty Fielding.

Arizona's Ryan Hogue and St. George's Nick Killpack had the low score of the afternoon wave with 66s, while six golfers, including 58-year-old former Utah Open winner Mike Malaska, came in at 67.

In all, 73 golfers shot par or better, including 30 scores in the 60s.

The golfer who got the most attention Friday was probably Masters champion Mike Weir, who is playing in the Utah Open for the first time as he tries to work his way into playing shape following elbow surgery last year.

The former BYU star was disappointed after shooting a 70, which put him in a tie for 31st place. He was most discouraged because he had been striking the ball better lately, but he was encouraged by the way he was able to get up and down with some clutch par putts.

"It wasn't very good today, but that's why I'm playing," said Weir who had his wife and two daughters following him during his round.

Weir struggled with his driving and was all over the place on the front nine when he made three bogeys to go with four birdies and two pars. On the back nine he settled down and made a birdie-2 at No. 13 and finished off his round with an up-and-down par from the bunker at No. 18.

"My game is not as efficient as I want it right now, but I played better on the back nine," he said.

Brown finished in a tie for second at last year's Utah Open and picked up right where he left off in 2011.

"It was a great start — I played well all day," Brown said. "I putted great. I had two bogeys out there and they caught the edge and lipped around. I had a lot of one-putts today."

Brown had five birdies in a row on the front nine from holes 3 through 7 and lipped out on a 10-footer at No. 8. He went to 7-under with a birdie at 11, made bogeys at 12 and 15, before coming back with an eagle at 16 and a birdie at 17.

Tolan also has a good track record in the Utah Open, finishing in the top 11 each of the past three years, including a tie for fourth in 2009, a tie for 11th in 2010 and a tie for seventh last year when he played in Sunday's final group.

"I like the course and I look forward to playing here because it's so well-run and so much fun," Tolan said. "Today I hung in there and made a lot of putts — I played the last 10 holes in 7-under."

The Finau brothers have been making golf headlines since they were youngsters and both are 22 years old now (Gipper turned 22 Sunday and Tony turns 23 next month). Tony has had more professional success, winning several events on the National Pro Tour, while Gipper has taken some time off recently to work on his schooling.

Tony, who started on the back nine, was only 2-under after bogeying the par-5 No. 1 hole, but made five birdies coming in. Gipper's round was highlighted by an eagle-2 at the 389-yard No. 3 hole when he drove the green and sank an 8-footer.

One of the more impressive scores Friday was turned in by 14-year-old Rhett Rasmussen, a freshman at Bingham High School, who is believed to be the second-youngest participant ever in the Utah Open.

Rasmussen, who earlier this year won his age group at Junior World in San Diego, fired a 3-under-par 69, which was the best amateur score behind Zac Blair's 67. When asked the key to his good round, he shrugged and said, "I hit them straight."

Defending champion Clay Ogden, who also won the tournament in 2007, struggled with three bogeys on his first nine, but went 3-under on his second nine for a 70.

After Saturday's round, the field will be cut to the low 60 scores plus ties. The winner of the tournament will receive $20,000.

Utah Open leaderboard

Derek Tolan 64

Zen Brown 64

Tony Finau 65

Gipper Finau 65

Dusty Fielding 65

Ryan Hogue 66

Nick Killpack 66

See complete scores on D11