Rory McIlroy surged to the top of the Dubai Desert Classic leaderboard as he completed his delayed second round with a series of birdies.

Gains on the 12th, 13th, 16th, 17th and last put the Ulsterman two shots clear of Wales' Jamie Donaldson on 15 under par.

Fog had ended the second day early but McIlroy was on fire when he returned to finish the final seven holes early this morning.

Paul Dunne and Graeme McDowell both missed the cut by one shot on four under. 

"That was pretty nice," said the 28-year-old on the European Tour website.

"I knew with the conditions this morning there were chances out there, obviously with the two par fives and 17.

"To take care of those and birdie a couple others, to finish five under for my last seven was a nice way to finish this morning.

"I didn't really have a score in mind or anything. I just wanted to go out there and play a good seven holes and hopefully get myself into contention for the last couple of rounds.

"I sort of did that and maybe a little bit more and it's nice to go into the weekend in the lead.

"Probably got a bit of a break between now and going back out there so I'll probably get a little bit of physio treatment, make sure everything's okay and hit some balls and practise.

"Look forward to getting out there again this afternoon."