Lee Westwood, oozing confidence, reached the last eight for the first time at the WGC-Accenture Match Play Championship, while Germany\'s Martin Kaymer became the biggest casualty in Friday\'s third round. World No 3 Westwood never trailed on his way to a 3&2 victory over American Nick Watney, but Kaymer, beaten by Luke Donald in last year\'s final, was ousted 4&3 by American Matt Kuchar at Dove Mountain\'s Ritz-Carlton Golf Club. Hunter Mahan completed another upset when he stunned US Ryder Cup team-mate and World No 5 Steve Stricker 4&3 after a sizzling display in the Sonoran desert, and Northern Irish World No 2 Rory McIlroy beat Spaniard Miguel Angel Jimenez 3&1. Kuchar became the first player to reach the quarter-finals, coming from one down after three holes with a rock-solid performance as Kaymer perpetually struggled on the tricky, heavily contoured greens at Dove Mountain. \"Matt played very consistently,\" Kaymer said. \"He didn\'t make any mistake really, but I made a few today unfortunately. \"I hit a lot of good quality golf shots today, especially the first nine. I didn\'t miss any golf shots really, but I just couldn\'t make the putts.\" Delighted Westwood, who will return to the top of the world rankings if he wins today\'s final, was delighted to beat Watney, having lost to the American in the second round in 2010 and again last year. \"I knew it was going to be a tough match against Nick,\" the Englishman said. \"It was nice to not make that hat-trick and to win, get through to tomorrow and see what happens on the weekend.\" In-form Mahan piled up nine birdies in dazzling sunshine, the last of them conceded by Stricker from just two feet at the driveable par-four 15th to end their third-round encounter. \"I felt good with my game,\" said Mahan. \"Irons, driving, everything, putting, chipping ... I just had a lot of confidence in it.\" McIlroy, who like Westwood would depose Donald at the top of the world rankings by winning the title, was delighted to produce his best form of the week. \"I\'m not saying I played terrible the first two days, but it wasn\'t like my best,\" the 22-year-old.