At one point on day two of the 149th Open Championship at Royal St George's, Collin Morikawa had surged into a four-shot lead.
After seven birdies and seven pars in his first 14 holes, the American had slipped the field and looked all set to shoot the lowest round in Major Championship history.
Instead, it was Louis Oosthuizen who ended up rewriting the history books.
Morikawa's scintillating iron play and smooth putting meant he needed to play the last four holes in 1-under to become just the second player after Branden Grace to shoot a 62 in the Majors. Play them in 2-under or better and he'd have the record on his own.
Anything seemed possible the way he was striping the ball but a bogey at 15 and a couple of wayward drives meant the 2020 PGA Championship hero had to settle for a 6-under 64.
That gave him a three-shot lead in the clubhouse but with glorious sunshine and calming winds greeting the afternoon starters, the low scores continued.
Oosthuizen had led the way after round one with a 64 of his own and another sweet-swinging display led to a 65 and a halfway total of 11-under.
That tally of 129 not only gave him a two-shot lead, it was also the lowest 36-hole score ever in the history of The Open Championship.
But Oosthuizen, the 2010 Open winner at St Andrews, has plenty of top-class names chasing him.
Don't count at pre-tournament favourite Jon Rahm either. The Spaniard hauled himself back into contention with a 64 to reach 5-under, six shots back.
Here are the best stats, quotes and social from Royal St George's after 36 holes.
Stats and facts
Oosthuizen's 129 was a shot fewer than the previous 130 tally shot by Sir Nick Faldo at Muirfield in 1992 and Brandt Snedeker at Royal Lytham in 2012.
This is Ooshuizen's fourth halfway lead in a Major. In the other three, he converted a five-shot lead to win by seven in the 2010 Open, slipped to 29th at the 2019 Masters and finished runner-up in this year's PGA Championship. He shared the 36-hole lead in the other two.
Starting with Darren Clarke here in 2011, a halfway leader has gone on to win four of the last nine Opens. Shane Lowry managed it two years ago.
Only two winners in the last 20 years were outside the top 13 at halfway - Francesco Molinari (T29 in 2018) and David Duval (T35 in 2001). Duval was seven off the pace while Molinari was six back.
Oosthuizen has hit 80.56% of greens in regulation so far compared to the field average of 65.94%.
Here's what some of the leading players said after Friday's play...
Louis Oosthuizen (-11, 65)
"Playing those last nine holes was probably as good a conditions you can ask for playing links golf. It was absolute perfect weather, little bit of a breeze but not really anything difficult I would say and I took advantage of that and played really well.
(After second places in the last two Majors) "I just need to pull it through and see if I can go one better on this weekend. The game is good, but I know it's a really good leaderboard. I have to play good golf this weekend if I want to come out first."
Collin Morikawa (-9, 64)
"Just sticking to what I've been doing. Yesterday I thought I played really well. Just wasn't hitting as many fairways. Was able to hit a few more fairways early on in the round today.
"When I'm in the fairway with a 9-iron or 8-iron I feel very comfortable. Not necessarily going straight at the pins but being aggressive with the lines I need to take and slopes you need to play. Yeah, sometimes you have those days where you're very fortunate to have good numbers, and today was one of those days."
Jordan Spieth (-8, 67)
"Those last six holes were kind of frustrating. I felt, I don't know, I think I need to bring more food on the golf course tomorrow. I got really just in a weird head space, like fatigued there on like the 13th green as we were waiting and hitting putts.
"I just didn't stay focused like I was early in the round. Wasn't very sharp. It's an easy solution for tomorrow. But the finish on 18 probably securing a second to last group on a Sunday is a good position to be in, but today was an afternoon where I was looking -- I was eyeing a number lower than what I finished at."
Dustin Johnson (-7, 65)
"I think the course it's definitely firming up. It was firmer this afternoon and it's definitely going to keep getting firmer if the weather stays like this. I mean, I like the position I'm in going into the weekend. Still going to have to play some really good golf if I want to contend on Sunday."
Scottie Scheffler (-7, 66)
"I've always done well on courses that are firm and fast, and so I wasn't too worried about coming over to play links golf the first time. Just needed to figure out the bunkers and the grass around the greens.
"I feel like I've gotten a really good feel for the positions on this golf course and where I need to attack and kind of stay -- or play a little bit safe. I feel like my game is trending in the right direction this week."
Jigger's hole-in-one, Peter Alliss tribute, DJ in a spot of bother, Louis surges clear, Hatton loses it, Koepka's late move, Molinari's bunker trouble and Friday's fashion twist
An ace for Jonathan "Jigger" Thomson.
A special tribute for Peter Alliss
Dj has tree trouble
Oosthuizen eagles 14 to go three clear
Hatton's had enough
Koepka stiffs one at 16
Molinari can't get out
Hoodies in fashion