Jordan Spieth hailed a "masterclass" from Rory McIlroy after the world number three won their first duel of the year at the Abu Dhabi HSBC Championship.
McIlroy had insisted he was not concerned about laying down a marker to Spieth after being drawn with the world number one and Rickie Fowler, but the four-time major winner certainly made an impression with an opening 66.
"It was a masterclass, the Rory that I have seen win major championships," Spieth said after a birdie on the last ensured he finished just two shots behind his playing partner and three behind clubhouse leader Henrik Stenson.
"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."
McIlroy had not played since winning the DP World Tour Championship in November, but the only evidence of that rust were two three-putt bogeys, each of which he immediately followed with a brace of birdies.
"It was a great way to start the year," McIlroy said. "I felt in practice last week I was swinging well and I came back mentally fresh and excited to play again. I could not be happier.
"I drove the ball well and that's one of the secrets around this course because if you hit it into the rough, it's difficult just to reach the green. I missed a few putts but holed a few I probably shouldn't have so it all evens out."
Spieth, who started his year by shooting 30 under par to win the Tournament of Champions in Hawaii by eight shots, admitted his driving was "short and crooked" for most of the day, but was more concerned with being warned for slow play on the penultimate hole.
" It was a bit odd," the Masters and US Open champion said. "I got a bad time on my putt on the eighth when they took us off the clock on that green and the guys behind us hadn't even reached the fairway on a par five.
"I understand that if you are being timed and you are taking longer than the allotted time, you get a bad time. I understand the rule but it doesn't make a whole lot of sense when our group had caught up."
Stenson underwent keyhole surgery on his right knee on December 9 and had been concerned about walking 18 holes, but carded eight birdies and one bogey to set the clubhouse target on seven under par.
"My expectations were not very high but it was a great start," the 39-year-old said. "I have missed the cut here the last two years so it was nice to get a good round in early.
"It was a bit of grind, more for my foot and hip than the knee, but I just have to take it easy and pace myself."