When Joaquin Niemann eagled Riviera's 10th hole on Saturday, his already phenomenal scoring was starting to look beyond absurd.
After driving the green at the short par 4, the Chilean drained his 22-foot putt to reach the dizzy heights of 21-under.
That's simply ridiculous. The event's best ever mark of 20-under was set 37 years ago by Lanny Wadkins and is the longest standing active 72-hole tournament record on the PGA Tour.
And yet here was Niemann crashing through that barrier after just 46 holes.
But then came his first real flat spell which might just give the chasing pack a glimmer of hope: Niemann played the final eight holes in 2-over to return to 19-under.
The good news for the 23-year-old is that it's something of a stretch to call his challengers a 'chasing pack'.
Although rookie Cameron Young is only three adrift after a pretty remarkable first three rounds himself, Niemann has a six-shot advantage over third place, is seven clear of fourth and eight clear of fifth.
Let's look at the front five on the leaderboard to decide if Niemann has this sewn up or whether anything hints at a final-round thriller.
Joaquinn Niemann - 19-under (63-63-68)
Niemann's only previous win on the PGA Tour came with a winning total of -21 in the Military Tribute at the Greenbrier so a repeat of that would break Wadkins' record.
His previous final-round scores at Riviera are 72 last year and 74 in 2019 (he missed the cut in 2020) which could hint at a late slip but he's playing to such a different level this week.
Niemann has held two previous 54-hole leads on the PGA Tour. In the first, he turned a two-shot advantage into a six-shot victory at the Greenbrier via a closing 64. In the second, he was tied at the top in the 2021 Rocket Mortgage Classic but finished second after a Sunday 68.
In short, on the limited evidence we have, he plays well with the lead.
Stats: Niemann ranks 1st in Strokes Gained: Tee To Green (10.485) and SG: Approach (6.613) although he actually lost strokes in those two categories on Saturday (-0.555 TTG, -0.786 Approach) which could be a minor concern.
His birdie count has also fallen each day (9, 7, 4).
Quotes: "I'm having the best time of my life right now. I just try to keep it calm, but yeah, I'm enjoying it a lot and I just can't wait to have a good day tomorrow.
"My speed has just been so good this week that the thing that helps a lot in these type of greens that they're so fast and every putt can run away from the hole pretty quick, so the speed has been good this week."
Cameron Young - 16-under (66-62-69)
The rookie is making just his 12th start on the PGA Tour but he has been in this position before after sitting second with 18 to play at last October's Sanderson Farms Championship.
On that occasion he followed rounds of 67-65-67 with a 68 to maintain his position and finish runner-up. He'd started the final day one back and he finished it one back.
Last month, Young was fifth and three back (same margin here) after three laps of The American Express, a multi-course event. That time he fell away to tied 40th after a Sunday 77.
Stats: Young is wielding the hottest putter in the field this week: he's gained 8.008 strokes on the field so far. He also tops the Driving Distance stats and is second for SG: Off The Tee.
Quotes: "Anytime you start Sunday three back, whether you're in tenth or second, you have a chance. Anybody out here can shoot 8 or 9 under and you just never know when it's going to be you on a Sunday.
"I'm still right there, I've only got one guy ahead of me. He's a great player and I know he's playing really well, but you just never know what can happen. Tomorrow that three shots can be gone in a hole and three shots can go the other way in a hole, so we'll just have to see."
Viktor Hovland - 13-under (71-64-65)
World No.4 Hovland has actually outscored Niemann by two shots over the middle two rounds but he still has another six to make up.
In three of his five worldwide wins, he'd started round four in the lead.
But he came from two back to win at Mayakoba for the first time and, notably, was also six behind the leader when he stormed through to land last month's Dubai Desert Classic with a 66.
The Norwegian shot a closing 67 here last year when tied fifth on his tournament debut.
Stats: Hovland ranks 2nd for SG: Approach (6.567) and had his best day in that category in round three (3.077).
Putting-wise, he lost strokes in rounds one and three but had a hot putter (3.692) in round two. He'll need a repeat of that performance on Sunday to have a chance.
He's also been making more birdies each day: 4, 7, 8.
Quotes: "There's a fine balance between being aggressive and pushing for birdies but not being reckless at the same time because there's some pins out there that are kind of tucked but they're kind of tempting to go for.
"Sometimes you can hit a great shot, land by the pin and you bounce over the green, you're in a tough spot.
"You definitely have to get some things going for you, make a couple putts here and there. If you can just kind of hit fairways and greens, you're never too far away because the greens are pretty small. It's just kind of hitting good shots and hope for the best."
Justin Thomas - 12-under (67-64-70)
Thomas gave himself hope with a second-round 64 to pull within six but is now eight adrift after a disappointing Saturday 70 which he rather saved with a pair of closing birdies.
Also against him is that's broken 70 just once in five previous Sunday rounds at Riviera. That was a 68 in 2017 and he'll surely need something far lower than that.
JT has 14 PGA Tour wins but he's never come from more than four back to win. However, in both of those - the 2016 CIMB Classic and the 2021 WGC-St Jude Invitational - he went from four back to win by three. A seven-shot swing on the leader here would sneak him into a play-off if all else remains equal.
Stats: Thomas has driven it well (1st for Driving Distance and 4th for SG: Off The Tee) but he ranks only 44th for Approach which doesn't bode well on a course where that category is usually an excellent pointer.
Collin Morikawa - 11-under (67-67-68)
Eight shots is the largest comeback in Riviera history (Ken Venturi in 1959) and as the man trying to make up that chasm is World No.2 Morikawa, we'll take a quick look at his chances.
Morikawa has six wins to his name across both Tours and has come from behind in five of those.
However, he was never more than three off the leader in any so eight behind seems far too much.
He's attempted eight-shot comebacks four times and never got anywhere near the winner, finishing 18th, 43rd, 20th and 14th respectively in those events.
Stats: He's actually having a good week with the putter, ranking 7th (4.761). But the rest of his game doesn't look strong enough.
Morikawa is only 28th in SG: Approach so he's underperforming in the area where he usually excels. That suggests he isn't a big threat.
Niemann must have a golden chance of closing this out and going wire-to-wire as the only player within six of him is a rookie.
But watch out for Hovland.
The Norwegian won from six back in Dubai recently and his Approach numbers and birdie count are going up as Niemann's are coming down.
Just maybe, this could be a thrilling final round after all.