World No 1 Jordan Spieth believes Rory McIlroy showed signs of his major-winning form during the opening round of the Abu Dhabi Golf Championship.
Spieth, who eased to an eight-shot win at last month's Hyundai Tournament of Champions, admitted he was disappointed with his driving during a four-under 68, but had plenty of praise for McIlroy's round.
The pair were part of the featured morning group alongside Rickie Fowler, but it was the Northern Irishman who came out on top with an opening 66 to get within two of the lead.
McIlroy was making his first appearance since winning the Race to Dubai in November and, having undergone laser eye surger, left an impression on the world No 1 with eight birdies during a strong start.
"It was a masterclass, the Rory that I have seen win major championships," Spieth said after closing his round with a final-hole birdie.
"It was very impressive today and minus one or two short putts, which is mainly just rust, it felt like he was on his A game.
"I didn't drive the ball well, which is really the key out here. So to shoot four-under with the way I felt with my driver is spectacular. I'm very pleased with that, but I need to play the par-fives better."
McIlroy got off to a fast start in his pursuit of a maiden Abu Dhabi victory and briefly held the outright advantage with three birdies in a four-hole stretch around the turn, with two three-putt bogeys the only blemishes to his card.
"It's a great way to start the year," McIlroy told Sky Sports 4. "I felt in practice last week in Dubai that I was swinging it well and I came back mentally refreshed and really excited to get playing again.
"I drove the ball really well and I think that's one of the secrets to this golf course. If you can drive the ball well and keep it in play because you can see because if you hit it in the rough it makes it difficult to even hit the greens.
"It (Abu Dhabi) has been a great way to start the year and I've always played well here, but I just haven't been able to get the victories.
"Hopefully I can change that this year and to start with a win here would be fantastic, so fingers crossed I can play like that over the next few days."
Watch the Abu Dhabi Golf Championship throughout the week live on Sky Sports 4 - your home of golf. Second round coverage gets underway on Friday from 7am