Ian Poulter shrugged off a migraine on Saturday before giving himself a major headache by spurning the chance to close the gap on the leaders in the British Open third round.
The 31-year-old Briton got off to a fast start with three birdies in six holes before making further inroads on par at the 11th and 14th.
But Poulter's charge came to a sudden halt when he dropped four strokes in three holes to the 17th.
"I've had a migraine for two days and had just cleared it up," the Englishman told reporters after finishing with a 70 for a three-over total of 216.
"I felt fantastic on the course today, hit the shots I wanted to but two bad shots are hard to take right now."
Poulter was referring to a pulled drive at the 15th which caused a double-bogey six and another poor tee shot two holes later which narrowly avoided water and led to a bogey.
"It's desperately frustrating," he said. "I also missed a three-foot birdie putt on 13 and probably three other easy birdie opportunities.
"I went through the field and could have been eight or nine under today. I was aware of the (bad) weather forecast, of what what would happen if you put in a decent score and I was five-under through 14 holes."
Poulter, who often attracts attention for his colourful dress sense, said he was driven by a desire to add to his seven European Tour victories.
"A few people may not believe it but I'm hungry to win golf tournaments," he said.
"I am not here to make up the numbers and I think I can go out there and prove a point."