Rory McIlroy and close rival Rickie Fowler are neck and neck after an entertaining opening round of the Abu Dhabi HSBC Golf Championship.
The duo's careers are becoming increasingly intertwined, with Fowler finishing in the top five of all four majors last year but McIlroy winning two of them and coming out on top in their singles match at the Ryder Cup.
And although the world number one began his year with a birdie on his opening hole, the 10th, he dropped back to level par just before the turn as Fowler moved into the ascendancy.
The American was at one stage in a share of the lead on six under but by then McIlroy, spurred on by his playing partner, was on the charge and five birdies on his final seven holes put him in a decent position.
Fowler then made his only bogey on the last to drop back to five under, alongside McIlroy, and two shots behind morning leader Thomas Pieters of Belgium.
McIlroy, standing alongside Fowler afterwards, admitted his game was raised by the 26-year-old.
"I was just trying to keep up with this guy," he said in quotes from the European Tour's official website.
"He was kicking me on, for sure. I didn't want to let him get too far ahead of me. I just wanted to try to stay as close to him as possible and thankfully I was able to do that."
The 25-year-old appeared in trouble on the third after his tee shot left him on the lip of a bunker, but he superbly managed to get his approach shot onto the green before holing for birdie.
That proved the catalyst for his round as he picked up shots on his next two holes before a nerveless 15ft putt on the seventh was followed by another birdie to lift him to 67 for his round.
"It's definitely a boost," he said. "It's not a shot I would practice too much, that's for sure. But from looking like you're going to make a bogey to making a birdie, that gives you a little bit of momentum and you can go on from there and luckily I was able to make a few birdies after that.
"The result was good, 67 was pleasing. How I got there in the end wasn't quite as pleasing. There's a couple of things that I need to work on if I want to have a chance to win."
Fowler, making his debut appearance in this tournament, made birdies at the 15th, 17th, first, fourth, fifth and seventh before dropping a shot at the last.
Nevertheless, he was satisfied with his display in only his third event since last September's Ryder Cup.
"I was a little shaky this morning," he said. "I haven't played in quite some time, so it's nice to get things off to a consistent start and throw some birdies in there.
"Unfortunately I made bogey at the last but I made some good swings coming down the stretch and I'm definitely pleased with the start."
Pieters, who has never won on the European Tour, claimed the outright lead shortly after Fowler had bogeyed with a birdie on the par-five 18th to complete a magnificent 65.
"It was nice to start out the season with a seven-under, so, I'm happy," he said.
France's Gregory Bourdy and Branden Grace of South Africa are in a tie for second, one shot adrift, while American Peter Uihlein is alongside McIlroy and Fowler on five under.
England's Tom Lewis is two shots further back but his round was remarkable for his hole in one on the par-three 200-yard seventh, the 10th ace in tournament history and third on that hole.
"As soon as I hit it, I knew I hit it good, coming in high, and I said, that's got a chance," he said.
"I was just like, 'perfect'. I was just pleased I didn't have to putt. The green there is tricky to read and obviously I hit a great shot."
Reigning US Open champion Martin Kaymer catapulted himself into the top 10 and could even look to move ahead of McIlroy and Fowler in his final five holes.
The German was four under after his first eight holes and although he dropped a shot before the turn, he began his back nine with back-to-back birdies.
He dropped another shot at the 12th but for the second time in his round, followed up a bogey with a birdie at his next hole.
Kaymer did pull ahead on the 15th and then moved joint top with his ninth birdie of the day two holes later.
The 2008, 2010 and 2011 winner missed an eagle chance on the last, his putt coming up just short, but he tapped in for birdie to claim the outright lead.
Finally, Rickie Fowler can team up with Rory McIlroy and actually win something. The young American played second fiddle to McIlroy three times on the big occasion last year but now he can toast success, albeit for a bit of fun in Abu Dhabi.