The 36-year-old is one shot behind England’s Justin Rose who leads the way with a fine opening six-under 65.  Oosthuizen shares second with Americans Rickie Fowler, Xander Schauffele and Aaron Wise.

The 2010 Open Champion began his round on the 10th, and made a fast start with an eagle at the par four 11th. There he holed a wedge approach from the fairway to vault his name up the leaderboard. 

“I think it was about 110 yards or something. And I hit a decent line and couldn't really see the where the second shot lands,” said Oosthuizen

“I just went on the reaction of the crowd that it was a good shot and obviously saw that they went nuts.”

Another birdie followed at the par five 14th, but he dropped a shot at the par four 16th to make the turn in two-under.

Two birdies in a row from the fourth helped, before another hole-out from off the green for birdie on the par four 18th gave Oosthuizen the perfect finish to his round.

“I was fortunate with the uphill lie in the bunker, I could get some height on the ball and just try to get it within four or five feet right of the hole to have an uphill putt. And it came out perfectly.”

In addition to his Open Championship title nine years ago, Oosthuizen has four second-place finishes in the Majors. The world-number 22 spoke about what it would mean to add the US Open to his list of victories. 

“I think just winning a major is already to me is sacred enough. To be able to win a US Open would be very magical to me.

“It would be something that anyone can dream of winning an Open and the US Open. I think Pebble to me is probably one of my favourite venue for a US Open. You're not going to beat the scenery and everything about this golf course, and it's just the weather we're having at the moment, it makes this week really special.”

The next best-placed South African is amateur Jovan Rebula who carded an impressive one-under 70 for a share of 28th on his US Open debut. The 21-year-old is the nephew of four-time Major champion Ernie Els. The pair played a practice round together, and Rebula said that experience helped him immensely.

“I got to spend a good bit of time with my uncle, had some practice rounds with him. So always being able to spend time with your family is always special,” said Rebula.

“To be able to have a chance to play in a US Open, never mind Pebble Beach, that's something that words cannot describe.”

Erik van Rooyen was the third South African on the leaderboard with an opening effort of level-par 71 for 40th place. Justin Walters was a further stroke behind on one-over 73 in a tie for 58th. Justin Harding signed for two-over 73 in a share of 77th.

Branden Grace settled for three-over 74 in 98th, while Els -  a former two-time US Open Champion in 1994 and 1997 - ended with a four-over 75 in 116th position. Dean Burmester was tied for 132nd with five-over 76 while Merrick Bremner battled his way to an eight-over 79 and 148th place.

- ANA