After opening with his lowest first-round score in 10 years, Estes avoided any bogeys and shot a 7-under 65 on Friday to take the lead after two rounds of the Reno-Tahoe Open.
The four-time PGA TOUR winner stands at 15-under-par 129, breaking by two shots the 36-hole tournament record set by Vaughn Taylor last year.
Estes, 40, is one shot ahead of first-round leader Will Mackenzie, who had a 5-under 67 on Friday.
Holding his first 36-hole lead in six years -- and looking for his first win since the 2002 Kemper Insurance Open -- Estes knows it will take a heck of a weekend to pull it off.
Scores over the first two days have been that good.
'It will take a lot under par to win this tournament if the conditions stay the same on the weekend,' Estes said.
The day's biggest story may have come from obscure Japanese Tour player Yusaku Miyazato, who carded two holes-in-one during a six-hole stretch.
Miyazato aced the 230-yard seventh hole with a 4-iron and the 173-yard 12th with a 7-iron and is believed to be the first player in modern PGA TOUR history to have two holes-in-one during a single round, the PGA said.
'The first ace was my second ace in my career,' said Miyazato. 'But the second one today was unbelievable. It was uphill, so I couldn't see it go into the cup.'
Tied for 17th overnight, Miyazato mixed his two aces with three birdies and a bogey to shoot 6-under 66 and climb into a tie for seventh place at 9-under 135.
Only two players have ever aced two holes in the same PGA tournament, and both did it in 1994: Bob Tway at the Memorial and Glen Day at the Greater Hartford Open.
'I am very proud to be a part of PGA Tour history,' Miyazato said.
Elsewhere at Montreux Golf and Country Club, 2001 Reno-Tahoe champion John Cook fired his second consecutive 66 and is alone in third place at 12-under 132.
Alex Cejka shot his second straight 67 and shares fourth place at 10-under 134 with David McKenzie and Nick Watney, who both had 68s on Friday.
Miyazato leads a group of five players knotted at minus-9, including 2002 PGA Championship winner Rich Beem, who had a 69 in his second round.
The cut line fell at 1-under 143 with 79 players making it to the weekend.
Among those missing the cut were 1999 Reno-Tahoe champion Notah Begay III and 1987 Masters champion Larry Mize, the only former major winner who missed the cut.
Beem joined Mark Brooks, Steve Elkington and Nick Price as the former major champions who made the cut in a field made weaker by the WGC-Bridgestone Invitational, which is playing opposite this event.
Taylor, the 2004 and 2005 champion and owner of almost every tournament scoring record, is in Ohio for the Bridgestone.