stated return to strokeplay golf on Thursday, finishing on one under par in the WGC-CA Championship first round and six shots behind the leaders. American Phil Mickelson, India's Jeev Milkha Singh, South African Retief Goosen and Thailand's Prayad Marksaeng shared the clubhouse lead after firing seven-under-par rounds of 65. Woods was making his first appearance in a strokeplay event since his playoff win at the US Open nine months ago. The world number one cut short his 2008 season in mid-June to have reconstructive knee surgery before returning to the PGA Tour at last month's WGC-Accenture Match Play Championship. Starting on the back nine, Woods bogeyed the par-three 13th after finding the bunker just short of the green and two putting. The 33-year-old then took another four on his 13th hole of the day where he found water but the biggest frustration for Woods, who made three birdies, was his putting. “I hit so many putts that looked good. I thought I hit my lines and thought I had the right speed but they just didn't go in,” said Woods who was philosophical about a score that equalled his worst on a course which is one of his favorites. “It wasn't like I hit bad putts. If I was struggling on the greens then I would be a lot more frustrated but I hit good putts and they just didn't go in. “That's all right. If you continue hitting good putts, they will go in,” he said. While all the attention was on Woods as usual with the crowds flocking to follow his round, Indian Singh enjoyed an excellent day. The 37-year-old birdied seven out of nine holes in a purple patch in the middle of his round after a bogey on the par-four 11th. “I'm very happy with the way I am striking the ball. I putted really well today, for the first time this year and I hope to keep that going,” he said. Asian tour regular Marksaeng finished his round in style with three birdies but the brightest finale belonged to Mickelson who chipped in on the 16th and 18th to share the lead. Padraig Harrington, James Kingston and Rod Pampling each shot 66. Louis Oosthuizen birdied four of his first five holes on the way to a 67, and Camilo Villegas - the Colombian who tends to play well in South Florida, where the Latin population shows up in droves to watch him - had four birdies on his final nine holes to shoot 67.