Rory McIlroy insisted he was not concerned about laying down a marker to world number one Jordan Spieth, but his golf was doing that for him in the early stages of the Abu Dhabi HSBC Championship.

McIlroy has not played since winning the DP World Tour Championship in November, but there was no evidence of any rust as he birdied four of his first six holes on Thursday.

Starting on the back nine at Abu Dhabi Golf Club, the four-time major winner got up and down from a greenside bunker on the par-five 10th and then holed from five feet for birdie on the 11th.

The 26-year-old missed from six feet for the hat-trick on the next and surprisingly three-putted the 13th from 20 feet, but bounced straight back with birdies on the 14th and 15th to join England's Richard Bland and Finland's Mikko Korhonen in the lead on three under par.

Spieth, who started his year by shooting 30 under par to win the Tournament of Champions in Hawaii by eight shots, opened with five straight pars before holing from close range for birdie on the 15th, while Rickie Fowler was one over after two bogeys and one birdie in the first four holes.

Another three-putt on the 17th cost McIlroy his second dropped shot of the day, but the 26-year-old again bounced back with a birdie on the par-five 18th and picked up another shot on the first.

That took the Northern Irishman back into a share of the lead on four under alongside Bland and Ryder Cup team-mate Martin Kaymer, who had birdied four holes in a row from the 15th. Kaymer has won this event three times, but amazingly blew a 10-shot lead during the final round last year.

Spieth had narrowly missed from 25 feet for an eagle on the 18th but tapped in for birdie and also birdied the first to remain just a shot off the lead alongside Henrik Stenson, who had feared he would struggle to walk all 18 holes in his first event since undergoing knee surgery on December 9.

Stenson had missed the cut on three of his last four appearances in Abu Dhabi, but a hat-trick of birdies from the second took the Ryder Cup star to six under par and into a share of the lead with Bland.

McIlroy was just a shot behind after his seventh birdie of the day from 15 feet on the third, with Spieth bouncing back from his first bogey on the second by coming within inches of a hole-in-one on the fourth.

US Amateur champion Bryson DeChambeau, whose irons are all cut to the length of a six-iron, was two shots off the pace after covering the front nine in 32 with one bogey, three birdies and an eagle.