San Francisco - World number one Rory McIlroy and Masters champion Jordan Spieth won their matches on Thursday to set up mouth-watering showdowns for a place in the last-16 at the WGC-Match Play Championship.
McIlroy took care of Brandt Snedeker 2-up to set up a grudge match with FedExCup champion Billy Horschel as the American won 3&2 over Jason Dufner to leave both men 2-0 in group play heading into Friday's head-to-head at TPC Harding Park.
World number two Spieth was too good for fellow American Matt Every 4&3 leaving him with a do-or-die clash with England's 26th seed Lee Westwood.
McIlroy seemed comfortably in control of the match at 2-up through 10 holes but Snedeker rallied with birdies on 11 and 12 to square the match.
McIlroy wrestled the lead back with a birdie on the 15th before closing it out on the 18th hole.
"I did what I needed to do against Brandt today. I felt like I played very solid tee to green and made a few birdies so that's nice," said McIlroy.
"The match tomorrow, it's win or go home.
"Billy seems like he's playing well. I'm looking forward to it. It's do or die."
Spieth has continued his hot form with the putter from his Masters triumph but knew it would count for nought if he could not back it up against Westwood.
"Win or go home (tomorrow)," Spieth said of his mindset.
"Lee is coming off of a win (in Asia) and playing well. It's going to be a tough match. It's going to be hard to keep making this many putts and this many birdies and I feel like I'm truly going to need to beat him."
World number four Bubba Watson made light work of fellow major winner Keegan Bradley 4&2 to set up a meeting with the man he conquered in a playoff to win the 2012 Masters, South African Louis Oosthuizen.
Oosthuizen, a former British Open champion won 2-up against Spain's Miguel Angel Jimenez.
American Rickie Fowler and Australian John Senden clinched spots in the round of 16 ahead of day three matches thanks to other results in their pools.
Fowler was a 1-up winner over Ireland's Shane Lowry while Senden took down former FedExCup champion Bill Haas 4&3 a day after upsetting world number three Henrik Stenson in 19 holes.
Among the 22 with no chance to advance are Stenson, defending champion Australian Jason Day, former world number one Adam Scott, Jimmy Walker, Ian Poulter and major winners Graeme McDowell, Bradley and Dufner.