No need to wait until Sunday for the Masters to come to life.

Brooks Koepka, Bryson DeChambeau and Phil Mickelson delivered enough excitement over the final two hours Thursday for quite an opening act at Augusta National.

Koepka, a winner in two of the last three majors, ran off four straight birdies in the middle of the back nine by overpowering a soft course. DeChambeau came within inches of two hole-outs over the last three holes as he closed with four straight birdies.

They each had a 6-under 66, giving them a one-shot lead over the 49-year-old Mickelson, who provided his own brand of entertainment.

Mickelson began the back nine with shots into the pine trees and the water, only to follow with four birdies over the next five holes, including a tee shot on the par-3 16th that stopped inches from the cup.

Tiger Woods missed all the action. He played earlier in the round and plodded his way to a 70. It was a solid start for Woods in his quest to end 11 years without a major, and he was atop the leaderboard briefly until a late bogey. He sounded satisfied.

"I've shot this number and won four coats, so hopefully, I can do it again," said Woods, who slightly miscalculated. The last green jacket he won in 2005 began with a 74. The goal was to not fall too far behind early.

Rory McIlroy's bid for the last leg of the career Grand Slam began with a 73, which featured six bogeys.

"I made five birdies -- that wasn't the problem," McIlroy said. "I just made too many mistakes, and that was the problem."

Even more surprising to McIlroy was no one from the early starters took advantage of soft turf from recent rains.

"It's there for the taking, and I'm surprised someone hasn't run off," McIlroy said.

And that's right about when Koepka and DeChambeau took off.

More impressive than the four straight birdies by DeChambeau was how he made them. After a two-putt birdie on the par-5 15th, his tee shot grazed the edge of the cup in the front left portion of the green. From the woods, he went just over the back of the 17th green and chipped in from 35 feet.

He didn't see until later how good his shot was into the 18th because he was in light rough short of the fairway bunker, unable to see the green but knowing it was good from the roar of the crowd. The ball ran true to the cup and smacked into the middle of the pin with enough force to knock it backward a few inches.

"I guess I should have pulled the flagstick," DeChambeau said.

He is not the only player to putt with the flagstick in the cup -- allowed under the new Rules of Golf -- just the only one to apply science to the decision.

Koepka shot his 66 while playing in the last group of the day, and not seeing very good golf alongside him. Jordan Spieth had to rely on his short game to salvage a 75, matching his highest score at Augusta. Paul Casey, coming off a victory three weeks ago in Florida, failed to make a birdie in his round of 81.

Blinders on, Koepka played bogey-free in his first time at the Masters in two years. He missed last year recovering from a wrist injury that left him wondering if he would ever play again. Then he won a second straight U.S. Open, held off Woods to win the PGA Championship and has established himself as a major player.

He holed out from behind the green at No. 12, picked up birdies on the par 5s and rolled in a bending 20-footer in between on the 14th.

Dustin Johnson and Ian Poulter were at 68, while Jon Rahm and Adam Scott were among those at 69.

Justin Rose, who returned to No. 1 in the world and was among the favorites this week because of his recent history at the Masters, opened with a 75.

"It's just a great test of golf to start out the first round of Masters," DeChambeau said. "And to be honest, it's great to sift through some of the really good players and maybe not so great players in this event right now. And look, it's not to say they are bad players. It's just it's very difficult out there and every aspect of your game has to be on point. So it's kind of nice, you can almost break away from the pack if you play well."