Rory McIlroy plays Miguel Angel Jimenez in the third round of the WGC Match Play on Friday hoping to stay on course to become world number one.
McIlroy will end the week at the top of the world rankings if he wins the knock-out event in Tuscon, Arizona.
The same incentive applies to Lee Westwood after the current number one Luke Donald was eliminated in Wednesday's first round.
McIlroy has so far beaten South African George Coetzee and Dane Anders Hansen.
The second seed is the only current major champion left in the tournament.
For the third day running McIlroy will be in the penultimate game as he tackles Ryder Cup team-mate Jimenez in the last 16.
In his match against Hansen, Northern Ireland's US Open champion drew first blood when the Dane bogeyed the third.
The experienced Hansen levelled on the fifth - with another bogey - but was behind again two holes later.
McIlroy birdied the eighth to go two-up, but promptly bogeyed the next.
The County Down man was one up with six to play and a key moment came when he chipped in to win the 14th after both men went into scrub by the green.
McIlroy went on to win 3&2.
McIlroy admitted the prospect of rising to the top of the rankings was on his mind.
"Everyone keeps telling me, so it is difficult to put it out of my mind," he said.
"It is a little bit of extra motivation this week knowing that if I can get through four more matches, I could go to the top of the world rankings which is obviously a huge moment for my career."