(CNN) -- Surprise British Open winner Louis Oosthuizen said a phone call from South African golf legend Gary Player gave him the impetus to pull off a stunning victory at St Andrews.
Oosthuizen, a 200-1 outsider before the tournament, cruised to a seven-shot victory on Sunday, the biggest winning margin in the sport's oldest tournament since Tiger Woods won by eight shots at the same venue in 2000.
Lee Westwood was second on nine-under-par, while his fellow Englishman Paul Casey, who was four shots behind Oosthuizen going into the final round, finished in a tie for third.
Oosthiuzen, 27, told CNN: Player "phoned me this morning and said 'have fun, keep calm, you're in the last round of a major and that's what you've worked for.'
"He said the crowd's probably going to be on Paul Casey's side, that's natural. But he told the little story about his first Masters when he played against Arnold Palmer.
"He said the crowd were really vicious and wanted to throw some stuff at him because he was beating Arnold. It was great a getting the call from him."
Nicknamed "Shrek" by his friends because of the gap between his front teeth, Oosthuizen held his nerve throughout the final day to shoot a one-under-par round of 71.
He was joined on the 18th green by his wife Nel-Mare and daughter Jana.
Oosthuizen became the fourth South African to win the Open after Bobby Locke, Player and Ernie Els and the victory propelled him from number 54 to 15 in the world rankings on Monday.
"I can't believe it. I don't know when it's going to sink in. It's been brilliant and it was just amazing," he said.
South African newspapers paid tribute to an unlikely hero on Monday.
"All hail King Louis" was the main headline in The Citizen, while The Times screamed "Louis you beauty!"
Oosthuizen won his first title on the European Tour title at the Andalucia Open in March and had missed the cut in seven of his eight previous major appearances.
But now he has the famous Claret Jug in his possession, he is targeting more major titles, starting with the US PGA championship at Whistling Straights, Wisconsin, in August.
"I've been swinging well for a while now and I think the win earlier in the season on the European Tour just got my confidence going," he said.
"It's just brilliant knowing that I can do it and I'm looking forward to the rest of the majors."