Rickie Fowler's victory over Ian Poulter topped the upsets of Day 1.
The possibility of upsets is a great attraction for an event like the World Golf Championships-Accenture Match Play Championship.
The biggest names can be quickly erased in the first round, and there was some of that on Wednesday.
And there were results like Jonas Blixt, an 11th seed, knocking off sixth-seeded Keegan Bradley, 2 and 1, and 10th-seeded Billy Horschel whipping seventh-seeded Jamie Donaldson, 6 and 5.
But here's a list of the six biggest upsets of the always-volatile opening round.
And don't be surprised if there are more in Thursday's second round.
Patrick Reed showed his toughness in Wednesday's match.
Patrick Reed is making his first appearance in the WGC-Accenture Match Play this week, and his inexperience here has made him an unproven commodity.
The other side of that is he was 6-0 in matches while leading Augusta State to two NCAA championships.
That college experience had to help in his opening match, as he ground out a tough 1-up decision over Graham DeLaet.
Reed was down two after six holes but was able to win the seventh and 12th to get the match even. The two exchanged wins on the 14th and 15th, but Reed took the lead for good with a par on the 17th.
Reed will now face George Coetzee in a battle of upset winners in the second round.
Matteo Manassero showed some of his promise Wednesday.
Twenty-year-old Matteo Manassero has carried a great deal of promise for a few years and obviously is in the early stages of his professional career.
His 5 and 4 thrashing of a former winner of the Match Play, Luke Donald, was impressive and gave golf fans more of a look at what this young man might turn out to be. To be sure, Donald is not the player he was when he won here in 2011.
How dominant was Manassero? Well, he won five of the first 10 holes, while Donald won just one hole in 14.
It will be interesting to see how long Manassero lasts into the tournament.
George Coetzee took Steve Stricker down Wednesday.
This qualifies as one of the big surprises because of how the two players were seeded.
George Coetzee is a relative unknown ranked 14th in his bracket. Steve Stricker, one of the best to ever wield a putter in the history of the game, was seeded third.
Coetzee jumped out early by winning the first two holes and turned that into a 3-up advantage and eventually won, 3 and 1.
But the fact that this was Stricker's first outing of the season, combined with the uncertainty of his brother Scott's health (he had a liver transplant Friday, per The Associated Press, via ESPN.com), might have a lot to do with his performance.
Stricker made a game of it, getting to within one through 14 but couldn't get the match back to even.
Peter Hanson handled Dustin Johnson with ease Wednesday.
Dustin Johnson, not related to Zach Johnson, might have been the second-hottest player in the game behind Zach Johnson coming into this week. How does finishing no worse than sixth in four starts in 2014 sound?
Johnson didn't bring that game with him to the Arizona desert, and he was handled rather easily by 15th-seeded Peter Hanson, 4 and 3. Hanson made three birdies, while Johnson made just one.
The long-balling Johnson has now lost in the first round five times in the last six years.
So much for long drives leading to an advantage in match play.
Richard Sterne pulled off the biggest upset of the day.
Zach Johnson left Marana, Ariz., Wednesday night with the distinction of being the only No. 1 seed in the Match Play to be eliminated on the first day.
When Johnson was last on a golf course in a PGA Tour event in mid-January, he completed a run of four straight top-10 finishes, including a win in the Hyundai Tournament of Champions in Hawaii.
The game's hottest player managed just two birdies in the 15 holes that were played before he was ousted, 5 and 4. Richard Sterne, from South Africa, was 3-up at the turn.
It was that kind of day for Ian Poulter in the first round of the Match Play.
One of the players in this match was a No. 14 seed, the other the acknowledged best match-play player in the world.
Rickie Fowler, a young man with an abundance of hype and talent but who has been painfully short of results to this point, is the 14th seed. Ian Poulter is the match-play master who had won 22 matches in the WGC-Accenture Match Play Championship.
On this day, Fowler played like a champion and Poulter didn't.
Fowler jumped out to a 3-up lead in just seven holes, and Poulter could get no closer than 2-up.
On the 17th hole, Poulter missed a 10-foot birdie putt that would have sent the match to the 18th.
This is the third time in the last four years that Poulter has lost in the first round.