STOCKHOLM -- British Open champion Louis Oosthuizen shot a 5-under 67 and was tied with Australia's Richard Green and Dustin Johnson of the United States after the first round of the Scandinavian Masters on Thursday.
Just four days after his runaway victory at St. Andrews, Oosthuizen started full of confidence on an overcast, breezy day at the Bro Hof Slott course with a birdie at the par-5 578-yard first hole.
The South African finished the front nine in 1-under 35. He collected five more birdies on the back nine, but was unable to take the overall lead after a bogey at the 13th.
"I had a good sleep, but I woke up tired again and the [British Open] win has definitely drained me," Oosthuizen said. "But the crowds were unbelievable, cheering me on to every green and every tee. I wanted to play nicely. The last thing I wanted was to put on a bad show."
"I need a break. I need a week off before going to America," Oosthuizen added. "I don't think I'm [supposed to be] back to South Africa until September but I felt like I wanted to say hi to my family and see everyone before I go."
Green reached his 67 after posting three consecutive birdies from the 11th. The Australian is going for his first European Tour win since 2007.
"My driving was exceptionally good," Green said. "[This year] I've struggled with the putter, I've struggled with my driving. Hopefully those two areas can stay with me this week."
Johnson, who finished eighth at the U.S. Open in June, completed the back nine in 33 after birdies at Nos. 12, 13 and 18.
Scottish Open champion Edoardo Molinari was one shot back after a 4-under 68. The Italian chipped in from the bunker for a birdie at No. 7 after a poor drive.
"The tee shot was a shank to be honest," Molinari said. "I think I hit a very good bunker shot because it came out very high and soft and then hit the flag and went in."
It was a mixed day for the Swedish players in front of their home crowd. Steven Jeppesen shot a 68. Two-time champion Jesper Parnevik was 3 over in his first competition since February, while Robert Karlsson shot a 1-over 73 after a double bogey at the first hole.
Defending champion Ricardo Gonzalez of Argentina shot a 72 and was five shots off the lead.