Graeme McDowell has revealed that he believed he was heading out of the WGC World Match Play Championship before edging past Hunter Mahan on Friday.

The Northern Irishman, who trailed in both of his first two rounds, fought back from two down to beat Mahan on the third extra hole, but admits that he thought his luck was going to run out.

"My head went down as I walked off the 16th green. I really thought I blew it," McDowell told reporters. "I genuinely thought I was done this time.

"I really didn't think there was any way back from that."

McDowell will now face Victor Dubuisson for a place in the semi-finals of the tournament.