Giant fans provide some relief from the soaring heat as players prepare for the start of the USPGA Championship in Tulsa

Bradley Dredge of Wales is one of the opening trio on the course as the tournament gets under way on Thursday

Camilo Villegas of Colombia enjoys a rare spot of shade on the 10th and moves into an early lead with a birdie on the 14th

Sergio Garcia of Spain also makes a bright start and moves to two under, before wresting the lead from Villegas

Defending champion Tiger Woods birdies his opening hole but struggles badly on the back nine to finish on one over par

Colin Montgomerie fires three early birdies for a share of the lead but blows his good work with three bogeys to end +2

Darren Clarke double bogeys the 10th and slumps to a seven-over 77 in the stifling heat

The lead changes hands at regular intervals, while Ernie Els produces a mixed bag to close off the pace

Markus Brier and Arron Oberholser cope best with the heat and take a one-shot lead over Woods and Rich Beem

Brier then drops a shot on the sixth and joins Rich Beem and John Daly just behind Oberholser, who leads at four under

Oberholser takes cover under a towel as he tries to defend his narrow lead from the chasing pack

Former champion John Daly, though, birdies 13 to get to four under and snatch the lead

But when Daly drops back, England's Lee Westwood joins him on three under before he double bogeys 17 to end one under

Unheralded Englishman Graeme Storm then surges to the top, reaching five under through 11 before parring his way home