Rory McIlroy is in tied third place and two shots off the lead after day one of the Abu Dhabi Championship – his first event since November.
McIlroy, 26, made eight birdies during his six-under-par 66, two shots fewer than world number one Jordan Spieth, who was in the same group as McIlroy.
American amateur Bryson DeChambeau leads on eight under with Sweden’s Henrik Stenson on seven under.
“It was a great way to start the year – I could not be happier,” McIlroy said.
“I felt in practice last week that I was swinging well and I came back mentally fresh and excited to play again.”
World number three McIlroy was playing for the first time since winning the DP World Tour Championship in November and the Northern Irishman’s performance impressed American Spieth.
“It was a masterclass, the Rory that I have seen win major championships,” said 22-year-old Spieth, who won the Masters and the US Open in 2015.
English duo Richard Bland and Andy Sullivan are tied for fifth on five under, while fellow Englishmen David Howell and Matthew Fitzpatrick are level with Spieth in tied seventh on four under.
DeChambeau carded seven birdies and an eagle in an impressive 64 to become the surprise leader in Abu Dhabi.
The 22-year-old describes himself as a “golf scientist” and has modified his irons so they are all the length of a six iron.
“It was quite incredible,” DeChambeau said of his round. “I had no expectations and was just able to freewheel a little bit and that allows me to do my best.”