Former champions Louis Oosthuizen and Jordan Spieth made brilliant starts as the delayed 149th Open proved well worth the wait at Royal St George's.

Oosthuizen, who won at St Andrews in 2010 and lost a play-off at the same venue five years later, carded a flawless six-under-par 64 to enjoy a one-shot lead over Spieth and Brian Harman, with 2009 champion Stewart Cink, Mackenzie Hughes and Dylan Frittelli a shot further back.

Former Masters champion Danny Willett led the early home challenge on three under alongside Justin Rose, Jack Senior and Andy Sullivan, who made the most of his late call-up into the year's final major after a number of players withdrew.

Already a runner-up in all four major championships, Oosthuizen took his unwanted total of near misses to six by finishing second in both the US PGA Championship at Kiawah Island and the US Open at Torrey Pines this season.

Asked how he copes with such losses, the 38-year-old South African said: "It depends if you lost it or someone else beat you. In both of those I was beaten by better golf at the end.

"It takes a little while but you have to get over it quickly otherwise it's going to hold you back from performing again."

Oosthuizen currently leads the putting statistics on the PGA Tour and is so pleased with that part of his game that his old putters could even be consigned to a watery grave.

"I've got a bag there at home that I might just throw in a river someday," Oosthuizen joked.

"I found one that I really like the look of and I worked on it. There were tournaments where I felt my stroke wasn't great and I would actually change that putter then for the round. I didn't want to have any bad memories of that putter being not good on the day."

Spieth, who claimed his first victory since winning the 2017 Open at Royal Birkdale in his native Texas in April, bogeyed the third but bounced back with four straight birdies from the fifth and also picked up shots on the 15th and 16th.

The former world number one fell to 92nd in the world rankings following a missed cut in his first event of the season, but the 27-year-old has since recorded six top 10s in strokeplay events, including a tie for third in the Masters.

"I look back and I had a chance to win at least one of the majors each year when I felt like I had no idea where the ball was going which, I guess, could be bad and good," the three-time major winner said.

"Golf is a game played between the ears, right? When it's not going great, you can certainly lose quite a bit of confidence in it. That was the first time I've had to really try and build confidence back up, and it takes time.

"By no means do I feel like I'm where I want to be mechanically yet, but this year has been a really, really good progression for me, and all I'm trying to do is just get a little bit better each day."

Four-time major winner Brooks Koepka returned a 69, while US Open champion and pre-tournament favourite Jon Rahm had to birdie the last to shoot 71, the same score as defending champion Shane Lowry.

England's Richard Bland had got play under way at 6.35am, the 48-year-old recognised for winning his first European Tour title at the 478th attempt in May and becoming the oldest halfway leader in US Open history last month.

Bland, who carded three birdies and three bogeys in his 70, added: "It was very special, very nerve-wracking. I was all right when I got on the tee but when he calls your name and yours is the first shot the nerves cranked up a little bit.

"I was hoping I might get a good draw but that was something else. I'm very grateful to the R&A for considering me for doing it."