Rory McIlroy and Lee Westwood are still on course for a semi-final clash at the World Golf Championships-Accenture Match Play Championship in Tucson.
McIlroy overcame Ryder Cup teammate Miguel Angel Jiménez 2 and 1 in the third round, while Westwood beat Tiger Woods' conqueror Nick Watney - the man who had knocked him out the last two years - by a 3 and 2 margin.
It was the first time in 12 attempts that the Englishman had made it into the last 16, but he looks in the mood to go much further.
He next plays Martin Laird, who defeated fellow Scot Paul Lawrie 3 and 1 in a game which could have big implications for the Ryder Cup qualifying race.
Victory on Sunday would put Westwood back as World Number One ahead of Luke Donald - McIlroy has the same target for the weekend - and so far he has repeated Donald's feat in winning 12 months ago, never trailing in any game and never being taken to the final hole either.
He has actually led for 48 of his 49 holes so far and said: "I feel in control of nearly every part of my game.
"I did some good work on my chipping last week and played some really nice ones. It was nice to get my own back. I didn't want to make it (losing to Watney) a habit."
He birdied the first two holes, went three up after the American missed the green at the ninth, then stretched the gap to four by almost holing his approach to the next.
Westwood was bunkered on the 12th and lost it to a par three, but he did wonderfully well to halve the 583 yard 13th in birdies after his chip hit the hole and rolled ten feet away. Halves at the next three finished things off.
Former Open Champion Lawrie had gone all 18 holes before beating Justin Rose and Ryo Ishikawa, but was in trouble from the moment he bogeyed the first and Laird birdied the long second.
Laird stretched his advantage to three "against the head" at the short 12th, holing from seven feet and seeing the 43 year old miss from five, but Lawrie's two-putt birdie on the next brought him back to two down.
It was all over, though, when Lawrie failed to get up and down from sand on the 17th.
McIlroy turned three up after some dazzling iron play. But for missing twice from under five feet and once from eight feet the 22 year old third seed would have been out of sight.
The gap twice came back to two early on the back nine, McIlroy twice fluffing chips, but he delivered the final nail in the coffin with another superb approach to the 17th.
Last year's runner-up Martin Kaymer found American Matt Kuchar too hot to handle despite two opening birdies, losing 4 and 3, while Hunter Mahan beat Steve Stricker by the same margin in a match between Ryder Cup colleagues.
Kuchar, a semi-finalist last year, was also at The Celtic Manor Resort and he is next for Mahan.
Another player from that match, Swede Peter Hanson, beat Brandt Snedeker 5 and 3 and will now face another American in Mark Wilson, a surprisingly easy winner over Dustin Johnson.
“I love match play,” said Hanson. “I think it's the best format ever. You only have to play one guy at a time. Here is so much fun and I think my attitude has been very good this week and I have been hitting this ball very well.”
McIlroy had to wait to discover his next opponent. Australian John Senden and Korean Bae Sang-moon were level with three to play.
McIlroy said: "I hit some really good irons and felt I hit a lot of quality shots, especially coming down the stretch when I needed to.
"I'm driving the ball really well and that's big positive.
"Miguel told me he hopes I go all the way and get number one."
Laird said after his win over Lawrie, who coached him as Open Champion over a decade ago: "It was surreal playing against him and a shame we were paired together.
"I really didn't play well the last two weeks, but my coach got me sorted out.
"I'm looking forward to playing Lee and if I keep playing like I am it will be a good game."
He lives in nearby Scottsdale and felt that knowledge of the desert conditions helped him, Lawrie more than once misjudging how far his ball was flying.
As he did against Masters Tournament champion Charl Schwartzel, Bae sank a short but testing putt on the final green to beat Senden and earn the right to tackle McIlroy.