When he destroyed the field to win the 2010 Open at St Andrews by seven shots, Oosthuizen looked to have the golfing world at his feet, but a second major title has eluded him.

Oosthuizen, 38, has finished runner-up six times, including at this year's PGA Championship and US Open, and he endured another disappointing final round of 71 at Royal St George's on Sunday to fall short once again.

The South African had started his challenge at Royal St George's with sublime rounds of 64 and 65 and after a solid 69 he led the field by one shot going into the final day.

Louis Oosthuizen salutes the crowd after making his first birdie of the final round on the 11th hole. PHOTO: Getty Images.

Oosthuizen looked flat during the final round, however, visiting two different bunkers on the way to a bogey at the par-5 7th hole as his playing partner Collin Morikawa started a run of three successive birdies that set him up to win the title by two shots ahead of American Jordan Spieth.

Oosthuizen dug deep to birdie the 11th hole, his tee shot hitting the flag before he sank a six-foot putt.

Another birdie followed at the 14th but Oosthuizen could only match Morikawa's pars at the last four holes.

One of the best ball-strikers in the game, Oosthuizen exudes an air of quiet efficiency on course, calmly plotting his way round and rarely showing his emotions.

Oosthuizen didn't front the media after his final round but he did take to Twitter to thank the Open crowds for their support.

Although he never looked happy on Sunday, Morikawa enjoyed playing with him.

"Louis is an outright amazing player and person," said Morikawa.

"He's just a great guy to play with. It's nice to see another guy just stripe it down the middle.

"Louis is consistent he really is. He's going to keep knocking at these doors, and I'm sure he's going to knock a few more down. He's just too good."

Oosthuizen will get another chance when St Andrews is the venue for the 150th British Open next year and he will hope to evoke memories of his 2010 triumph to end his long wait for another major victory.