OWINGS MILLS, Md. — From back-to-back eagles to back-to-back shots in the water, Bryson DeChambeau had a little bit of everything Saturday in the BMW Championship, a wild ride at Caves Valley that ended with him tied for the lead with Patrick Cantlay.

Right went it looked as though DeChambeau would use sheer power and a remarkable touch with the putter to run away from the field, his blunders on the back nine made him settle for a 5-under 67 and still looking like the player to beat.

Cantlay’s classic style worked just fine, too. He didn’t drop a shot until a tee shot into deep rough on the 18th that led to bogey and a 66.

The action at the top was so furious that DeChambeau went from a one-shot deficit to a three-shot lead in two holes on the front nine, and Cantlay went from a four-shot deficit to a one-shot lead in two holes on the back nine.

Cantlay ran off three straight birdies early on the back nine that allowed to make up so much ground so quickly, mostly due to DeChambeau hitting into the water on the par-5 12th (bogey) and the par-3 13th (double bogey).

They were at 21-under 195, and Sunday had the trappings of a two-man race.

Sungjae Im birdied his last two holes for a 66 and was three shots behind. The group four shots back included Rory McIlroy, who had a bogey-free 65 and only made up two shots on the lead.

Crisp-hitting Abraham Ancer of Mexico (66), Sam Burns (65) and Sergio Garcia (67) also were in the group four shots behind. The biggest disappointment belonged to Jon Rahm, the world’s No. 1 player, who had three bogeys and no birdies over the last six holes and shot 70.

He fell five shots behind. That’s not typically a massive deficit, it just seems like one on a course where birdies are available to everyone at any time.

Rahm was doing his best to keep up, three shots behind, when he missed the 13th green to the left for bogey, missed the fairway to the right on the 14th for another bogey and had to settle for par on the par-5 16th. He closed with a bogey from the fairway bunker.

On this course, on this day, that meant losing ground quickly.

Then again, momentum and position changed without notice.

Cantlay was one shot ahead early and all it took was two holes for him to fall three behind without doing anything wrong.

This was all about DeChambeau, who charged up the sun-baked gallery with a 25-foot eagle putt on the par-5 fourth hole and then drove onto the front of the green on the 322-yard fifth and made a 55-foot putt that looked good when it was halfway to the hole.

At that point, it looked like a runaway on a Caves Valley course suited perfectly to him with soft conditions and wide fairways. Even the errant shots turned out well.

He hit one drive so far left down the hill at No. 8 that DeChambeau had to walk some 30 yards back to the fairway because he couldn’t find a sprinkler with a yardage on it. He hit that to 30 feet and made the birdie, stretching his lead to four shots.

And then it all changed. The mud on his ball contributed to a wild shot to the right and into the water, turning certain birdie on No. 12 into bogey and a two-shot swing when Cantlay got up-and-down from just off the green for birdie.

DeChambeau’s tee shot on the par-3 13th found the water, which led to double bogey and a three-shot swing when Cantlay holed a 35-foot birdie putt.

Sunday has more than just the trophy at stake. The top 30 in the FedEx Cup advance to the final event at the Tour Championship next week. Garcia was poised to moved into the top 30 with Hudson Swafford and Erik van Rooyen among those lurking.

Patrick Reed was home in Houston recovering from bilateral pneumonia. He needed a lot to go right to stay in the top 30 and has a more reasonable chance than at the start of the week.

As for the Ryder Cup, Tony Finau and Xander Schauffele dropped out of the top 30 at Caves Valley, and Cantlay could grab the sixth and final automatic spot only if he were to win.