By Helen Ross, PGATOUR.COM Chief of Correspondents
MARANA, Ariz. -- Here are recaps from quarterfinal matches on Saturday at the World Golf Championships-Accenture Match Play Championship:
Rd. 4: Mahan def. Simpson, 1 up
Hunter Mahan played the 18th hole on Saturday afternoon for the first time in four matches this week as he beat the reigning U.S. Open champion.
In fact, the last time Mahan played the 18th hole was in his opening match last year as he embarked on a successful march to the championship. The sixth hole of that match against Zach Johnson last year also was the last time Mahan trailed -- which is an impressive streak of 141 holes.
Mahan and Simpson both played well. They halved the first four holes before Mahan drew first blood with a 17-footer for birdie at the fifth hole.
Simpson birdied the par-5 eighth to square the match but Mahan's 26-footer at No. 10 put him 1 up again. Simpson then got up-and-down from the greenside bunker at the par-5 13th for another birdie to square the match.
Mahan got the final edge, though, when he drove the 15th green and two-putted for birdie from 56 feet. The next three holes were halved with pars and Mahan's record improved to 14-4.
"Difficult match against Webb," Mahan said. "Great competitor, great player. I knew it was going to be a tough one, and it was. It was really a seesaw battle. I don't think either one of us really gained too much momentum, it was so back and forth.
"I made a couple nice up and downs and made some nice putts today. In the afternoon that's kind of what led me to victory, obviously making the par on 16 gave me the 1 up lead and I was able to finish it down the stretch. But tight match and really could have gone either way."
SCORECARD STATS: Mahan made five birdies and didn't drop a shot to par. Simpson made five birdies and one bogey.
HOLES WON: Mahan won three holes. Simpson won two holes.
NEXT OPPONENT: Mahan plays Ian Poulter, who beat Steve Stricker 3 and 2 in the quarterfinals.
Day def. McDowell, 1 up
Jason Day earned his way into the semifinals in a big way by taking down two major champions on Saturday.
After dispatching Bubba Watson with relative ease in the morning, Day had to dig deep in the afternoon when neither he nor Graeme McDowell had their best stuff.
The 2010 U.S. Open champion won the first hole with a conceded birdie and made another one at the third to go 2 up. When McDowell bogeyed the fourth and seventh holes, though, the match was square again.
Day took the lead for the first time with a birdie at the par-5 11th hole. McDowell then squared the match with a birdie at the 14th but Day answered with a 3-footer at the next to get back to 1 up.
Another see-saw spurt saw McDowell and Day trade wins with pars at Nos. 16 and 17. So Day took a 1-up lead to the 18th hole where he two-putted from 42 feet for the win and McDowell missed a 16-footer for birdie to extend the match.
"It was very stressful out there today," Day said. "I feel like my mind is going every which way right now. Just to play the way I did on the back nine was very, very special. The whole game today felt really, really nice, and I'm looking forward to tomorrow.
"You know, myself and G Mac, we really didn't play our best, but you've just got to do enough. That's because you're just playing against a guy that's across the tee from you. I've got Matt Kuchar tomorrow, and I know he's very slow and steady, hits a lot of fairways and greens and can roll the rock when he can, and I'm looking forward to that."
SCORECARD STATS: Day made four birdies and two bogeys. McDowell made five birdies and four bogeys.
HOLES WON: Day won five holes. McDowell won four holes.
NEXT OPPONENT: Day plays Matt Kuchar, who beat Robert Garrigus 3 and 2 in the quarterfinals.
Poulter def. Stricker, 3 and 2
This battle of former Accenture Match Play Championship winners didn't disappoint.
Ian Poulter put a damper on Steve Stricker's 46th birthday, though, as he pulled away in the middle of the round for his 24th vicory in 33 matches in this global event.
Poulter actually made his first -- and only bogey -- in his last three matches at No. 1 as Stricker was in the process of making birdie there to go 1 up. The Englishman got back on track quickly, though, as he rolled in birdie putts of 5 and 40 feet on the next two holes to take the lead the bulldog would not relinquish.
While Poulter was sizing up that 40-footer, Stricker actually was looking at his own 7-footer for birdie at the third hole to possibly win it himself.
"Steve is always a tough person to beat, and he was going to play some good golf today," Poulter said. "That's exactly what he did. I managed to keep my nose in front, I guess, with a typical match play swing on the par-3 third hole. It looks like Steve is going to be going up right there, and I hole, he misses. And from then on I sort of took over and got myself in front."
Poulter holed a chip at the sixth hole for a 2-up lead and then drained a 25-footer for eagle at the par-5 eighth to go one better. Stricker's 4-footer for birdie at the 10th hole narrowed the gap to 2 down but Poulter responded with two consecutive birdies to take a 4-up lead.
A conceded birdie at the 14th hole gave Stricker a glimmer of hope at 3 down but the next two holes were halved with a birdie and a par and Poulter was on to the next round.
SCORECARD STATS: Poulter made six birdies, one eagle and one bogey. Stricker made four birdies and one bogey.
HOLES WON: Poulter won six holes. Stricker won three holes.
NEXT OPPONENT: Poulter plays Hunter Mahan, who beat Webb Simpson 1 up in the quarterfinals.
Kuchar def. Garrigus, 3 and 2
Robert Garrigus came to Dove Mountain to play in his first Accenture Match Play Championship brimming with confidence.
Matt Kuchar, though, had the experience and his steady game won out over the grip-it-and-rip-it-style of Garrigus.
Kuchar never trailed in this quarterfinal match, winning the second hole with a 4-foot birdie after Garrigus missed from 6 feet. He went 2-up when Garrigus made bogey at the third hole but Kuchar did the same at the fourth.
Kuchar's birdies at the sixth and ninth holes gave him a 3-up advantage at the turn and he went one better at No. 10 when Garrigus made bogey. But Garrigus won the 12th hole with a par when Kuchar couldn't get up and down from the greenside bunker and the 13th with a 25-inch birdie putt to claw his way back into the match.
Kuchar then made a 4-footer for birdie at the 15th hole to get back to 3 up, and the win was assured when the two men halved the 16th with pars.
Kuchar has lost to the eventual champ last two years -- bowing to Luke Donald in the 2011 semifinals and Hunter Mahan in the quarters last year. He has a 13-3 record at this event.
"He let me have a couple of holes early," Kuchar said. "That was key. He battled back but I've been playing steady golf."
SCORECARD STATS: Matt Kuchar made five birdies and three bogeys. Garrigus made three birdies, three bogeys and one double bogey.
HOLES WON: Kuchar won six holes. Garrigus won three holes
NEXT OPPONENT: Kuchar plays Jason Day, who defeated Graeme McDowell 1 up in the quarterfinals.