The good, bad, and ugly from Day 1 at WGC-HSBC Champions

The first World Golf Championship of the season got underway Thursday in Shanghai, China at Sheshan International Golf Club.

Dustin Johnson, Jon Rahm, Hideki Matsuyama, Jason Day, and Phil Mickelson headline the 78-player field competing for the $9.75-million purse.

Here's a look at the good, bad, and ugly from the first round at the WGC-HSBC Champions:

Good

Brooks Koepka

The reigning United States Open champion vaulted to the top of the leaderboard, carding seven birdies and an eagle against one bogey en route to an opening-round 64. Koepka found eight fairways, 14 greens in regulation, and was rock solid with his putter, averaging 1.571 putts per GIR.

"Anytime you're making putts and you're keeping it in the fairway, you're going to shoot good," Koepka told the Golf Channel after the round.

Kiradech Aphibarnrat

Aphibarnrat is making his first PGA Tour start in over a year, but sits just one back of Koepka, thanks to a nice little run in the middle of his round. The 28-year-old from Thailand, who started his day at the 10th, made seven straight birdies beginning on the par-4 16th hole.

Bad

A shank by Stenson

The 2016 Open champion showed a bit of rust on Day 1, shanking his approach shot on the par-4 fifth hole well right of the putting surface. Stenson, who's one of the best ball-strikers in the game, tossed his club to his caddie in disgust after the mishit. The Swede would recover, however, finishing the hole with a par. He went on to card seven birdies, three bogeys for a round of 68.

Molinari's ice-cold putter

While the leaders enjoyed a successful day on the greens Thursday, the same could not be said for Francesco Molinari. The Italian is ranked dead last in putts per green in regulation, averaging 2.077 on the rugs. Molinari posted a 5-over-par 77.

Ugly

Si Woo Kim

For the first time in his PGA Tour career, Kim found every green in regulation, yet he was unable to take advantage of the remarkable statistic. The 2016 PLAYERS champion was the only player in the field to be perfect with his approach shots, but was only able to sign for an unremarkable 1-under-par 71. The 22-year-old tossed in a four-putt double-bogey on No. 3, and a three-putt bogey on the 15th.

Shutout for Sterne

Richard Sterne was the lone player unable to write down a birdie on his scorecard Thursday. Seventy-seven players registered at least two budgies, while Kiradech Aphibarnrat and Haydn Porteous led with 10 each.

(Photo courtesy: Action Images)