Updated

Marana, AZ (SportsNetwork.com) - Ernie Els cruised to an easy win over Jordan Spieth, while Jason Day fended off Louis Oosthuizen in Saturday's quarterfinals at the WGC - Accenture Match Play Championship.

Els, the eighth seed in the Gary Player bracket, rolled to a 4 & 2 win over the third-seeded Spieth. Els is the only former WGC and major champion left in the semifinals.

Day, the second seed in the Bobby Jones bracket, held off the eighth-seeded Oosthuizen, 2 & 1, at The Golf Club at Dove Mountain.

"We both played well today," Day said. "I've always loved match play since I was a kid. You've just have to grind at it and keep fighting to the end,"

Els will take on Victor Dubuisson in the semifinals. Dubuisson, the seventh seed in the Sam Snead bracket, held off fourth-seeded Graeme McDowell, 1-up.

Day will face Rickie Fowler in the other semifinal match. Fowler, the 14th seed in the Ben Hogan bracket, rallied to beat fifth-seeded Jim Furyk, 1-up.

The semifinals will start at 9:05 a.m. ET, while the 18-hole final and consolation match are slated for the afternoon.

Els, who had played poorly in his first three matches but advanced, never trailed against Spieth. He made a 4-footer for birdie on the second, but Spieth birdied the fifth from three feet away to square things up.

The duo traded wins at six and seven before Els birdied the eighth to take the lead for good. After three halves in a row, Els made a 6-foot par putt on No. 12 to push his lead to 2-up.

Els, 44, and Spieth both missed the 14th green, but Els got up and down for par and was 3-up with four to go. After they both birdied the 15th, Spieth missed a 7-foot par putt to lose the match.

"I obviously played relatively solid golf," Els stated. "I had a pretty nice start, I made a couple of birdies early. We played the fourth hole really bad, both of us. But I felt like I played okay. I gave him No. 7, but from then on I played okay golf. I got up and down when I needed to."

Spieth was making his debut at this event and was bidding to become the youngest-ever winner.

"I didn't have my swing, and I was a little mental midget out there. Actually kind of embarrassing, looking back," admitted Spieth. I was dropping clubs and whining to my caddie, and you can't do that. You've got to keep your cool. Ultimately, I just wasn't there mentally today. I don't know what it was."

McDowell didn't lead until the 18th hole or later in his first three matches, but on Saturday he eagled the second to take a 1-up lead. He stuffed his tee shot inside four feet at No. 3 and kicked that in for birdie to go 2-up.

The 23-year-old Dubuisson, who won the Turkish Airlines Open last year on the European Tour, birdied the fourth to trim his deficit. At the par-4 seventh, Dubuisson made birdie to square the match.

McDowell knocked his approach to seven feet on the ninth, but lost the hole when he missed the putt and Dubuisson chipped in for birdie.

The pair traded wins at 11 and 12, and a par on 13 was enough for McDowell to square the match one again. Both players missed the green at the 16th, but Dubuisson got up and down for par to move 1-up.

They both made short par putts to halve 17, then Dubuisson got up and down for par at 18. McDowell then missed an 18-footer for birdie to give Dubuisson the match.

Day, who has advanced to the semifinals for the second straight year, was conceded the first. Oosthuizen took a drop out of a bush on the second, but knocked his third to 20 feet and poured that putt in for a birdie that squared the match. Oosthuizen followed with another birdie on the third to go 1-up.

Day, 26, birdied the next two to regain a 1-up lead. He also birdied the ninth to move 2-up, then saved par from eight feet out on 10 to keep that lead. The Australian was conceded the 11th to move 3-up.

Oosthuizen, who battled a tight back the whole round, was conceded the 13th to get back within 2-down. The duo halved the next two holes with birdies, then after matching pars at 16 and 17, Day was off to the semifinals.

"Especially on the long irons and driver (the back hurt), but I'm used to it and I've learned to play with it," Oosthuizen admitted. "I played nicely, just a few errant tee shots."

Fowler, a Ryder Cup teammate of Furyk in 2010, ran out to a quick lead in their match with three birdies in the first four holes. Furyk fought back to take the sixth and seventh, however.

Fowler, 25, answered with birdies at nine and 11 to regain a 3-up lead. Furyk, who was on 15 straight American Ryder Cup or Presidents Cup teams from 1997-2012, then showed his mettle.

He birdied the 13th and made it two in a row as he drained a 12-footer for birdie on No. 14. Furyk squared the match with another birdie on 15 and a par at 16 gave him a 1-up lead.

At the 17th, Furyk's chip got away from him and he failed to make a long par putt to square the match. Fowler made another par at 18, and that was enough to win the match as Furyk once again failed to get up and down for par from short of the green.

"I forced him to make some birdies," said Fowler. "I knew it was going to be tough for him to keep on doing that, so I just stayed patient and made some good swings coming in. It's match play and anything can happen."

NOTES: If Els can hang on to win the title, he would be the oldest winner in event history ... All four players remaining have winning records at this event - Day is 12-3, Dubuisson 4-0, Els 16-14 and Fowler 6-3 ... Of the four semifinalists, Day has played the most holes (73) while Dubuisson has played the fewest (69).