DiMarco had an eagle and six birdies enroute to his 63.
LAS VEGAS (AP) -- Marc Turnesa topped the leaderboard for the third straight day in the Justin Timberlake Shriners Hospitals for Children Open, shooting a 3-under 69 on Saturday to take a one-stroke lead over three players.
The PGA Tour rookie had a 21-under 195 total at TPC Summerlin. He opened with rounds of 62 and 64.
Chris DiMarco (63), Michael Allen (64) and Ken Duke (67) were tied for second.
Matt Kuchar was tied for the lead with Turnesa with a hole to play, but closed with a double bogey for a 71. He was two strokes back at 19 under along with Zach Johnson (70) and Chris Stroud (67).
DiMarco eagled Nos. 9 and 16 and added six birdies. He played the last six holes in 6 under for his best round since a 62 in the 2003 Phoenix Open. After finishing in the top 30 on the money list from 1999 to 2005, he has missed 15 cuts in 26 events this year and is 143rd on the money list with $474,314.
"It's nice to be back in the hunt," DiMarco said. "It's a birdiefest out there. So for me to shoot 9 under today, I definitely played catchup, and that's all you want to do is play catchup and give yourself a chance for Sunday on the back nine. That back nine is fun because a lot of things could change. A lot could be done.
"To me, that makes golf exciting. I think fans want to see us make birdies and eagles and shoot low numbers and win tournaments like that rather than just try to hold on with bogeys and pars."
Another big mover was the 49-year-old Allen, who quickly moved to 17 under with three birdies and eagle on the first four holes.
Duke moved up five strokes by making eight birdies that offset three bogeys.
Johnson, who won the Texas Open last week, has made only seven bogeys in his last seven rounds, but two of them came in the third round.
Twelve players were cut at 8-under 208 following Saturday's round, leaving 71 players in the field.