Rory McIlroy blasted golf's "stupid rules" after being handed a two-shot penalty for an incorrect drop in the third round of the Abu Dhabi HSBC Championship.
McIlroy thought he had carded a 68 to finish 11 under par and just one shot behind leader Craig Lee, only to be told before he signed his card of a possible infraction by Dave Renwick, caddie to his playing partner Ricardo Gonzalez.
Renwick felt McIlroy had not taken full relief from a spectator crossing on the second hole and when video evidence proved inconclusive, McIlroy and European Tour chief referee John Paramor headed back to the par five to examine the area in question.
It was then determined that McIlroy's left foot had been touching the white line denoting the crossing and a two-shot penalty was applied.
"I'm going to go and hit the gym so hard," a clearly frustrated McIlroy said. "I'm going to run myself into the ground to try to get some of the frustration out.
"There are a lot of stupid rules in golf and this is one of them."
McIlroy, who said he had "better things to think about" than keeping up to date with the rules, added: "I hit my second shot on the second into the left rough but on the spectator crosswalk. I took a drop and played my shot but I did not notice my left foot was still on the line and you need to take full relief.
"We went out to see it again and see my divot and it was clear I could not have played my shot with my feet anywhere else. It's unfortunate. If anything it was a disadvantage because I dropped it in a bad lie and did not make birdie.
"I have to try to make up the shots as early as possible tomorrow. It gives me a bit of extra motivation."
It is not the first time that McIlroy has fallen foul of the rules in Abu Dhabi, the former world number one being penalised in 2012 for brushing away some sand that was not on the green but which lay between his ball and the flag.
On that occasion it was playing partner Luke Donald who pointed out the error and McIlroy admitted both Donald and Renwick had done the right thing.
"You have to adhere to the rules of this game and he (Renwick) was pointing out something he thought was questionable," McIlroy added. "He was just doing what I guess anyone would."
The incident overshadowed both Lee's chance to claim a first European Tour title and the brilliance of Phil Mickelson earlier in the day, who charged through the field with a sparkling 63.
Mickelson made the halfway cut with just one shot to spare after rounds of 73 and 70, but insisted on Friday he had "a good, low round in me tomorrow" and was as good as his word, carding nine birdies, an eagle and two bogeys.
His last birdie on the 18th came in typical Mickelson fashion, the Open champion attempting to reach the green in two from 230 yards away in a fairway bunker, only to hit a terrible shot into a sandy waste area, play a superb low pitch to 30ft and hole the putt.
"It was not a smart decision out of the bunker to go for the green, but I don't know, that's just what I do," joked Mickelson, who finished 10 under par to share second place with India's Gaganjeet Bhullar.
"Bones (his caddie Jim Mackay) did not like the decision and I don't blame him. It wasn't probably my smartest play.
"I hit a terrible shot but because it was sitting on a fairly hard, packed lie, I was able to go in steep and keep it low underneath the trees and I had plenty of green to work with.
"I will still be back a few shots, I anticipate, heading into tomorrow's round but I love the fact that I'm in contention and I have an opportunity (to win) here in the first week of the year.
"What I like is that it feels better each day. The first day, I felt terrible. The second day, half of it started to come around and today it started to feel pretty good and hopefully I'll be able to build on it again tomorrow."
Lee, whose best finish on the Tour came when he lost a play-off to Thomas Bjorn for the Omega European Masters last September, has a two-shot lead on 12 under after his 69 and is relishing the chance to take on some of the world's biggest names.
"It's exciting," said the 36-year-old from Stirling, who has been reaping the benefits of an artificial putting green installed in his front garden by his brother. "The quality of the players behind me is nothing I have been used to before.
"I can't control what they are going to do, I just have to go out and play the best I can. I can look back on last year when Jamie Donaldson won (holding off the likes of Justin Rose) and say it's possible and fairytales do happen."