SOUTHPORT (AFP) - Rory McIlroy was left to rue a lack of consistency as he all but kissed goodbye to his chances of winning a second British Open title on Saturday (July 22).

The Northern Irishman could only shoot a one-under-par 69 in largely favourable conditions in the third round at Royal Birkdale as he crawled forward to two-under overall for the championship.

That is nine strokes behind the leader Jordan Spieth, surely too big a deficit to claw back in Sunday's final round.

McIlroy failed to capitalise on a good start to his round which saw him birdie three of the first five holes.

"I've always been good when I get off to fast starts being able to keep it going, and I didn't today. And I needed to, that's the disappointing thing," said the world number four.

McIlroy dropped shots at the 7th and 8th before another birdie at the 9th, but there was then a calamitous double-bogey six at the 10th when he found sand off the tee and then landed in thick rough to the left of the green with his third shot.

Another birdie at the par-five 15th was not enough to make up for that - especially as it came after he missed a great eagle chance - and his disappointment was there for all to see as he came off the 18th.

"It's hard to think big picture now, I'm just off the golf course and I'm a little disappointed," he said.

Despite coming into the championship on the back of some poor results, the 2014 Open winner had been hopeful of getting his hands on a fifth major this week.

That hope is surely gone, but he was remaining upbeat ahead of his final round.

"This week has been a step in the right direction, there's no doubt about it," added the 28-year-old.

"And I need to pick myself up, play a good round tomorrow (Sunday) and hope for some bad weather. And hope for some guys to struggle. And we'll see what happens.

"Yeah, I definitely feel like today was an opportunity lost to get right in the mix going into tomorrow."