Several times DeChambeau had him on the ropes before Cantlay somehow survived and came through.
A similar story could be unfolding in this week's TOUR Championship.
Cantlay started the week with a two-shot lead over the field courtesy of sitting top of the FedEx Cup standings.
And despite Jon Rahm throwing a series of big punches at him in a frantic finish at East Lake on Friday, Cantlay still has his lead.
Rahm, who started the week four shots back from the leader, halved the deficit by shooting a 65 to Cantlay's 67 on day one.
The Spaniard threw down another 65 in round two, ending his day with a three-birdie barrage: a burst which showed his determination to knock Cantlay off top spot.
The Californian had other ideas. Just when Rahm threatened to catch him, he countered with birdies of his own at 17 and 18 to stay out in front.
His lead is down to a shot but Cantlay is showing an admirable ability to keep cool and change gears when put under threat.
That late surge from the top two separated them from the field.
DeChambeau and Justin Thomas both fired 67s but they're now back at -11 and -10 respectively. It will take some effort to reel in Cantlay and Rahm this weekend.
Here are the best stats, quotes and social from East Lake after 36 holes.
Stats and facts
Cantlay has had five previous 36-hole leads/co-leads on the PGA TOUR. He's yet to convert any of them.
Cantlay was an accumulative 10-over in his three previous East Lake appearances. He's 7-under for his first two rounds this week.
Cantlay is 1st for Strokes Gained: Tee to Green (5.752) but just 22nd in SG: Putting (-1.285).
Five of Rahm's six PGA TOUR wins have come when trailing after 36 holes.
Rahm's total of 130 is the second-lowest opening 36 holes in tournament history.
Rahm ranks 2nd for both SG: Tee To Green (4.221) and SG: Putting (3.246).
As for the lowest score this week, Rahm is leading the field by three shots.
130 Jon Rahm
133 Patrick Cantlay, Kevin Na, Billy Horschel
Given what he's done so far along with his record of winning from behind, Rahm has to be the bet going into the weekend.
Here's what some of the leading players said after Friday's play
Patrick Cantlay (-17, 66)
"I thought the two rounds were very similar, mostly mistake-free, both rounds, and I hit the ball pretty well, kept the ball in control, fat side mostly, and had really nice speed on the greens and just didn't make very much.
"Every putt out there is important and I know they will be important when I get there later on the weekend. So, yeah, it was nice to finish with a couple birdies and kind of validate the patience that I had all day."
Jon Rahm (-16, 65)
"At this point it just feels like we played two rounds and I'm going to go into the weekend in a great position. That's about it. Starting four shots back over 72 holes it truly isn't that much. It's one shot a round and that is absolutely nothing. I mean, bigger leads have been overcome in a lot shorter time.
"I've been able to get a lot of good up-and-downs, and avoiding those mistakes is what allows me to keep going. Hopefully I can just keep playing those final holes really well and give myself a chance on the weekend."
Justin Thomas (-10, 67)
"It was scrappy. It was a grind. Disappointing. I mean, to finish the way I did was definitely disappointing. But to be even 5-under with how I was driving it was pretty impressive. I just really, for as good as I drove it yesterday, and I felt as in control as I was, I hit some really squirrely drives and try to go figure that out on the range here this afternoon.
"But, yeah, I mean, I'm close. I'm in a good spot going into this weekend. Obviously I would like to be a little closer but there's nothing I can do."
Tony Finau (-9, 67)
"I hit more fairways today, which you got to do on this golf course. From the fairways you can give yourself some looks. So I got some nice momentum.
"I made a great par save on 14 and then a great shot on 15 to kind of get me going, just to finish off my round. Had a great look on 16 that I hit a good putt on, didn't go in. 17, I made birdie, and then two perfect shots into 18 to give me a great look for eagle. I wouldn't take that putt back, I hit it perfect and it just slid by the hole."
Rory McIlroy (-8, 66)
"I hit a few more fairways, or at least if I did miss fairways, I was just missing them.
"I got off to a poor start and then once I got it going there on the back nine and just kept hitting good iron shots pretty close and converting a few of them. And then I finished with a flourish. I birdied those last three holes and played those really well."
Jordan Spieth (-8, 67)
"I feel really good. I actually feel like I'm still in this golf tournament, maybe seven back (actually eight) with two rounds to go, but the way that I'm playing, the way I feel over the ball and the way I'm driving the ball, I feel if my putter gets hot, then can I make that up."
Cantlay dialled in, Rahm's hot finish, Thomas nails a bomb, Na's surprise putt and Spieth's big annoucement...
Cantlay's approach at 13: how did it stay out?!
Rahm sinks a 25-footer at 17
And just misses for eagle at 18
JT from downtown
Na wasn't walking this one in
Jordan expecting first child