Defending champion Jason Day was among the high-profile names to crash out of the WGC-Cadillac Match Play Championship on day two in San Francisco.
The new round-robin format means that every player still has one more group game to play, but Day, Ian Poulter and Graeme McDowell suffered their second defeats of the tournament to end their hopes of reaching the knockout stage.
A loss to Branden Grace ended Day's bid, while Ryder Cup teammates Poulter and McDowell were condemned to defeats by Gary Woodland and Harris English respectively.
Lee Westwood came from three behind to beat Mikko Ilonen and set up a group-deciding match with Masters champion Jordan Spieth after the American's 4&3 victory over Matt Every.
Rory McIlroy's 2up win against Brandt Snedeker means that he will need to beat Billy Horschel to earn a place in the last 16.
Justin Rose kept his tournament alive with victory over Anirban Lahiri on the first extra hole, but there was disappointment for his close friend Henrik Stenson, whose win over Brendon Todd was cancelled out by John Senden's win against Bill Haas.