Rory McIlroy admitted he was disappointed with his efforts in the opening round of the Charles Schwab Challenge, as he returned to PGA Tour action with a two-under par opening round of 68 in Texas.
The first event on the PGA Tour since the coronavirus shutdown in March saw a high-quality field assemble at Colonial Country Club, with 16 of the world's top 20-ranked players in the competition.
Justin Rose and Harold Varner III are tied for the lead on seven under par after the opening round, with Graeme McDowell one shot behind McIlroy on one under par and Open Champion Shane Lowry in a battle to make the cut after a disappointing one over par 71.
Playing in a group alongside Jon Rahm and Brooks Koepka, McIlroy struggled on bumpy greens as he was one of the last groups out on the course and he admitted he needs to improve on Friday.
"Uneventful," was the word he used to describe his opening round. "I made three birdies and one bogey and it was disappointing. It was one of those days when I put myself in a position to hit a low score, but my distance control and my wedges were a little off. Then the putting got a little difficult at the end of the day with slow and bumpy greens.
"Hopefully we will have some better greens to play on going out early tomorrow and I can shoot a lower score."
McIlroy went on to admit the absence of fans at the first PGA Tour event to be played after the Covid-19 pandemic did not have as big an impact on the event he was expecting.
"It felt good to be back," he added. "I thought it was going to feel a little more different and while it was a little strange not having anyone around, we are so concentrated on what we are doing, so once I got into it I didn't feel it was much different out there."
Justin Rose hit the ground running as he shot a blemish-free round of 63 to top the leaderboard in impressive fashion.
The world number 14, starting on the back nine, birdied four of the his first seven holes and then picked up shots on each of the first three holes after making the turn.
Rose said a bit of luck on the opening hole had set him on his way as he overcame some wayward shots to birdie his first hole.
"I got some momentum," he said on Sky Sports Golf. "I didn't play particularly well on the first six or seven holes but the putter was really hot.
"I got into a nice rhythm and I could have maybe got in the clubhouse better but I rode my luck a little bit."
Rose felt the performance was reward for the work he managed to do during the hiatus.
"I've worked hard for sure," he said. "I haven't just sat around. I had the opportunity to get better. My season wasn't going particularly well up until the Players Championship so you try to look at the positives.
"Obviously it's been a tough situation for everybody across the world, there are some dire circumstances, but you've got to look at yourself, your personal situation, and think, 'How can I make the most of this?'"
Harold Varner III joined Rose at the top of standings after the opening round, with the duo holding a one-shot advantage over Venezuelan Jhonattan Vegas and Mexico's Abraham Ancer.
Dustin Johnson did not enjoy his own return to action quite so much as the world number five stumbled to a one-over 71, carding four bogeys in a rusty round.
Ian Poulter was in a group tied for 10th place after a round of 66 while Phil Mickelson - fresh from his challenge matches with Tiger Woods during the shutdown - could only manage a one-under 69 to sit in a share of 38th place.