Open Championship: Jordan Spieth, Louis Oosthuizen in early lead

They've each got a single Open Championship victory, but the narratives around Jordan Spieth and Louis Oosthuizen are very different.

Spieth, the onetime Golden Child, has rediscovered his form after four years spent wandering in golf's wilderness. Oosthuizen, meanwhile, never lost his form ... if we define "form" as "runner-up, time and time and time again."

Either way, both ended the morning draw of the 149th Open Championship at the top of the leaderboard, Oosthuizen leading at -6, Spieth a stroke back.

The last time we saw Oosthuizen in a major, he was in the final pairing at the U.S. Open last month, but unable to hold off Jon Rahm's charge. It was yet another runner-up finish for Oosthuizen, his sixth since winning the Open Championship in 2010.

Oosthuizen took a little while to get going, but finished with a flawless bogey-free card, holing two birdies on the front nine and four on the way back in.

Spieth, meanwhile, played like the last four years since his victory at the Open Championship were but a mirage. After an early bogey, he ran off four straight birdies on the front nine, and another two on the back. His stroke was confident in a way Spieth hasn't been for years:

It's a long way to Sunday and another Open victory. But Spieth and Oosthuizen are already co-favorites to win at +500, per BetMGM. Three days from now, one of them could very well hoist the Claret Jug for a second time.

The day's most confounding round came from Will Zalatoris, who drained one shot from the fairway:

...but also missed a putt that was about the length of this sentence:

Zalatoris was fortunate enough to tee off in the morning, and ended the day at -1. The Open Championship always offers a very different look to players who tee off in the morning versus the afternoon, and on Thursday, the morning draw won the weather lottery. Virtually all of the Thursday leaders, who included Brian Harman at -5 and Stewart Cink at -4, teed off in the morning. By the afternoon, the winds had rolled in, causing trouble for the last groupings — or "games," as they call them at Royal St. George's.

Rory McIlroy, still looking for major redemption after seven long years, seemed to begin the day well enough, birdieing his first hole — a full five strokes ahead of his first hole at the last Open Championship. But he would go on to bogey three straight holes on his front nine.

For PGA Championship winner Phil Mickelson, the news was even worse: nine bogeys against exactly zero birdies, ending the day in dead last. Justin Thomas, Adam Scott, Patrick Cantlay and Patrick Reed were among the other big names who found themselves buried deep in the leaderboard after Thursday.

With the cut line looming, some notable names will have to hope that the weather plays out in their favor on Friday.

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Jay Busbee is a writer for Yahoo Sports. Follow him on Twitter at @jaybusbee or contact him at jay.busbee@yahoo.com.

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