R1 LEADERBOARD US unless stated -6 S Lowery, A Cejka (Ger) -5 J Smith, B van Pelt, J Driscoll, B Geiberger Selected others: -2 P Mickelson, J Rose -1 J M Olazabal (Spa), S Garcia (Spa) level V Singh (Fij), B Langer (Ger)

Lowery, boosted by seven birdies, led for most of the day before being caught by Cejka, who had a bogey-free round.

Three-times winner Mark Calcavecchia and French Ryder Cup star Thomas Levet were among a group of 12 players on 67.

And defending champion Phil Mickelson started with a 69, the same score as Britain's Justin Rose and one better than Spaniard Sergio Garcia.

"I had a chance to go low and didn't quite do it, but there's three more days, so we'll see," said Mickelson.

"I didn't hit a fairway on the front nine and I struggled. On the back side, I hit every fairway but one and shot three under.

"I'd like to try to put it together tomorrow for the weekend because I love playing the weekend in contention here. It's just a really fun thing to do."