Rory McIlroy has often shot himself out of contention in the first round of the Masters, but the Northern Irishman has managed to flip the script and pump life into his hopes of completing the career grand slam.

McIlroy, playing in conditions made tougher by shifting winds, carded a one-under-par 71 at Augusta National on Thursday (local time) that was his lowest opening-round Masters score since 2018 and left him six shots behind leader Bryson DeChambeau.

"I held it together well. It was a little scrappy. The conditions are tricky," McIlroy said after mixing four birdies with three bogeys.

"Hard to fully commit to shots out there at times just because the wind ... it's hard to commit to where the wind direction is at times."

McIlroy, who has missed two of the past three cuts at the Masters, was even par when he made the turn on a rain-softened Augusta National layout after mixing two bogeys with a pair of birdies.

The world No.2 went on to birdie the 12th and 14th holes to get to two-under, but had an underwhelming finish where he failed to take advantage of his chances.

McIlroy was unable to get up and down for birdie at the par-five 15th, missed a seven-foot birdie at the par-three 16th, bogeyed 17 after his tee shot found the trees, then had to scramble for par after missing the green at the last.

"A little wasteful coming in," McIlroy said.

"I had a good chance for birdie on 15 in the middle of the fairway and didn't take that. Missed a shortish one on 16 and then the bogey on 17. Probably turned a three-under into a one-under there at the end.

"But overall still not a bad score, and obviously a lot of golf left to play."

McIlroy has been in contention several times at the Masters but seems to be hampered by one poor round each week, most memorably in 2011 when he began the final round with a four-shot lead but endured a harrowing back-nine collapse.

But he is encouraged by his start and has not thrown away his chance this week to complete his collection of golf's major titles and join Gene Sarazen, Ben Hogan, Gary Player, Jack Nicklaus and Tiger Woods as winners of the career grand slam.