Updated

Rory McIlroy and Tiger Woods, the top-2 ranked players in the world, both lost in their first-round matches Thursday at the World Golf Championship - Accenture Match Play Championship.

McIlroy lost to Shane Lowry, 1-down. McIlory and Lowry have played together for years in Ireland. Charles Howell, one of Woods' closest friends, took down Woods, 2 & 1.

There were two matches left on the course as play was suspended Thursday evening. Carl Pettersson was 1-up on Rickie Fowler as they played the 18th hole. The winner of that will next face Lowry. Francesco Molinari and Gonzalo Fernandez-Castano were all square through 15 holes. That winner gets Howell in round two.

Those two first-round matches will resume on Friday morning at 11:30 a.m. (ET), while the second round gets underway at 11:20 a.m. at The Golf Club at Dove Mountain.

Snow halted play on Wednesday and the start of Thursday's action was delayed until 3 p.m. while the players waited for the snow to melt.

The other two top seeds - Luke Donald and Louis Oosthuizen -- both escaped tough matches. Donald fended off Marcel Siem, 1-up, and Oosthuizen took down Richie Ramsay, 2 & 1.

McIlroy was 2-up after four holes, but Lowry fought back to square the match as he took the sixth and seventh. After McIlroy won the ninth with a par, Lowry went on a run that turned the match in his favor.

He chipped in for par and the win on No. 10. After going over the green on the par-5 11th, Lowry again chipped in, this time for birdie. McIlroy matched that birdie, but couldn't match his playing partner at the 12th.

Lowry birdied the par-3 12th and rolled in a 5-foot eagle putt at No. 13 to go 2-up.

"My short game is the best part of my game. The pitch shot on 11 was just a straight forward chip, and I fancied it. The next one I was just trying to get up and down for the half, and it went in. That kind of got me going," said Lowry in a television interview. "Then I hit a lovely 5-wood to 5 feet at the next and that got me going for the rest of the round."

The duo traded wins at 14 and 15, before McIlroy birdied the 16th to get within one down. They matched pars at 17.

Lowry found sand off the tee at 18, and more sand with his second shot. McIlroy had an opening, but dumped his approach in the same greenside bunker as Lowry. McIlroy blasted within a foot and was conceded par. Lowry chipped to three feet and made the putt to win the match.

"We both gave each other a few holes, and I hit a few too many loose iron shots out there. I drove the ball really well, I just couldn't take advantage of that," McIlroy said in a TV interview. "I could have been 3-up or 4-up after five holes, but sort of let him get back into the match and he had a nice little run on the back nine. Just left myself too much to do."

Woods, despite not making a bogey all day, never led against Howell. Howell birdied the second to go 1-up, but Woods birdied the fifth to square the match.

Howell regained a 1-up lead with another birdie at the par-5 eighth. Woods took the 13th with a birdie of his own, but it was all Howell from there.

At the 15th, Howell converted a birdie effort to go 1-up. He rolled in another birdie try at 16. Woods failed to birdie the 17th and Howell easily 2-putted for par and the win.

"Of all the days that we played at Isleworth, I can't think of a day that I did (beat Woods). He's the best of all time, I knew I had to play my best to even have a chance. Fortunately, I holed a few nice ones there at the end," Howell said on TV.

Woods, a three-time winner of this event, hasn't made it past the second round since his last win in 2008.

"We both played well. We didn't make a bogey in the group," Woods told Golf Channel. "He made a couple more birdies than I did."

They could have stopped after 16 due to darkness, but played on because in Woods' eyes they were both playing well, so why stop?

In the Bobby Jones Bracket, where Lowry won, majors champions Jim Furyk, Graeme McDowell and Bubba Watson all won, while Zach Johnson, Padraig Harrington and Dustin Johnson were beaten.

Howell is in the Gary Player Bracket, where Webb Simpson and defending champion Hunter Mahan cruised to 5 & 4 victories. Lee Westwood and Jason Dufner, the second and third seeds, also lost leaving the fourth-seeded Simpson as the highest remaining seed in that region.

Donald is the top seed in the Sam Snead Bracket, where second-seeded Adam Scott fell 2 & 1 to Tim Clark. Nick Watney, 2010 winner Ian Poulter and 2001 champ Steve Stricker also moved on.

Oosthuizen is the top seed in the Ben Hogan Bracket, where four of the top six seeds advanced. Justin Rose, Sergio Garcia and Matt Kuchar all moved on, but former major winners Ernie Els and Keegan Bradley lost their matches.

NOTES: The Woods-Howell match was the only one without a bogey ... Only two matches went extra holes -- Garcia needed 20 holes to dispatch Thongchai Jaidee after losing the 16th and 18th holes when play resumed, and Westwood lost on the 19th hole to Rafael Cabrera-Bello after also dropping the 18th hole.