Patrick Cantlay's lead shrunk to a single stroke at the end of the second round of the Travelers Championship on Saturday.
The 19-year-old UCLA star shot a 60 on Friday, the lowest round ever by an amateur on the PGA Tour, and had a four-stroke lead when play was suspended by darkness.
But Johnson Wagner finished his second round with a 63 Saturday and is 12-under for the tournament, one behind Cantlay going into the third round. Nick Watney and Shane Bertsch are at 10-under. Eight others are four strokes back.
The cut line was at 4-under par, the lowest on tour this season. First-round leader Jim Renner was among those who failed to make it.
Cantlay had just played 36 holes in one day, coming off a whirlwind week in which he was the low amateur at the U.S. Open.
''I just finished some finals two weeks ago,'' he said. ''I just finished my freshman year. I'm pretty tired, to be honest. It's been a month of golf every day. Sprinkle in a couple finals, and I'm pretty tired.''
In what already has been a month to remember, Cantlay turned in his most inspiring moment yet Friday. Last week, the sophomore-to-be said the earliest he would turn pro would be ''after I get my degree.'' But after two strong rounds put him atop the leaderboard, he was starting to soften.
''I'm going to stay amateur definitely for the Walker Cup,'' Cantlay said of the premier amateur event in September at Royal Aberdeen. ''And my plan is to stay amateur until I finish college.''
Taking advantage of soft conditions and preferred lies on the soggy TPC River Highlands, Cantlay tied the tournament record set by Tommy Bolt in 1954 when it was played in Wethersfield.
Cantlay birdied the final two holes to reach 13 under. After shooting a 67 on Friday morning in the rain-delayed first round, he had eight birdies and an eagle in the afternoon. It was his second eagle of the day on the par-5 13th.
He said he had no idea that he was setting an amateur record.
''I knew where I was. I knew I needed to make eagle on 18 for 59,'' he said. ''It's tough to hole it from 152.''
But he came close. His approach landed just above the hole and rolled back to just over 2 feet below the pin.
''I thought it had a chance, it was covering the flag pretty good,'' he said. ''It takes some luck.''
The way his month has been going, he might have expected it to go in. Cantlay received the Jack Nicklaus Award from the Golden Bear himself on June 5 at the Memorial, and the next day qualified for the U.S. Open at a sectional site filled with PGA Tour players. Then after opening with a 75 at Congressional, he followed with rounds of 67-70-72 to become the low amateur, finishing in a tie for 21st.
Despite his youth, he has been around the game long enough to realize he still is only halfway there.
Wagner wasn't the only challenger. Nick Watney and Shane Bertsch were just two-shots back. Bertsch shot a second round 63 and Watney had consecutive rounds of 65. Eight others were at 9-under.
Players had perfect scoring conditions Friday with rain-softened greens and little wind. And because of the wet conditions, players were allowed to lift, clean and place their golf balls hit in the fairway, another big advantage.
The cut line was at 4-under par, the lowest on tour this season.
''A day like today, play good in the first round, you just kind of keep it going,'' said Vaughn Taylor, one of those at 9-under. ''Generally, your swing feels the same and your game feels the same, so you just kind of stay in it and just keep playing.''
An amateur hasn't won a PGA Tour event since Phil Mickelson in the 1991 Northern Telecom Open in Arizona. If Cantlay wins, he would have 60 days to decide whether to accept a spot on the tour and the two-year exemption that goes with it.
Four players have shot 61s at the TPC River Highlands course. The last was Kenny Perry in 2009.
Tour rookie Jim Renner shot 29 on his first nine holes and finished his first round with a 63, good enough for a one-stroke lead heading into the afternoon.
But he started his second round with a bogey, a par and a double bogey and finished the day at 3 under, and out of the tournament.
Renner had played in just one Tour event before this season and earned his card though qualifying school. He grew up in Plainville, Mass., and said this tournament was the first PGA Tour event he ever attended.
''I think I walked about four holes and realized I was ready to go home,'' he said. ''I was 14.''
The shot of Friday came from Heath Slocum, who holed a 160-yard shot across the water to eagle the signature 17th hole. He finished his two rounds at 7 under.
But Cantlay stole the show, and received a standing ovation from the sparse crowd as he walked up the 18th fairway.
''It's just one round,'' he said. ''It was a good round, and I played really well. Nothing bad happened. I'm really proud of it, but I've got a couple more rounds to play.''
