Garcia - who claimed his first major at Augusta in April - scored a brilliant hole-in-one at the island green that is the 17 at the TPC Sawgrass course in Florida, setting the stage for Scott who immediately followed him.
"When I hit it, the wind went straight into us, and I'm glad I hit it hard, because usually I hit my wedge 138, 140 [yards], and that thing flew 125", Garcia said.
"I hit a good shot, but.it can do anything".
Making his first start since claiming a maiden major title at Augusta National, Garcia had been four over par for his first six holes at Sawgrass after four-putting the fifth, the same hole he six-putted in the third round previous year. "It kind of made quite a poor round into - not a great round but a decent round". Two players failed to make the cut entirely.
Masters champion Sergio Garcia and Rory McIlroy were among the later starters, with McIlroy paired with world number one Johnson and Justin Thomas. I don't know, it can do anything. He finished with a 1-over-par round of 73, putting him in a tie for 66th, six strokes behind leaders William McGirt and Mackenzie Hughes. Day, however, made three bogeys over his last four holes and had to settle for a 2-under score.
Day's victory at Sawgrass 12 months ago was his seventh in 17 events, but he has recorded just one top-10 finish in 2017, although his form has been badly affected by his mother's battle with lung cancer.
Garcia said it was nice to post an ace after getting off to a rocky beginning.
After starting on the back nine at Sawgrass, Day birdied the 11th, 13th and 16th to reach the turn in 33, before holing from 65ft across the first green. "I felt a little bit nervous early on after the high from the Masters". It's been a busy week and at the beginning I wasn't really in the tournament. "Maybe because I needed it after the start I had". He walked off the green with a double-bogey five.