For the first time since the 2005 Players Championship three players are battling for the top spot at the same event.

On that occasion it was Vijay Singh, Tiger Woods and Ernie Els. This time it is Woods, Phil Mickelson and Westwood.

No European has been Number One since Nick Faldo in 1994, but if Westwood wins on Sunday Woods will have to finish second in the event to hold him off.

And if Westwood is second on his own he would take over at the top providing Woods is worse than ninth and Mickelson does not win.

As for Mickelson, who has already missed several chances to dethrone Woods for the first time, a win would guarantee it and even a top-four finish would be good enough if Woods is outside the top 37.

The tough part for both the challengers is that Firestone is the course where Woods has triumphed on his last four visits - and a US PGA Tour record seven times in all.

But he has also, of course, failed to win anywhere so far this season and was only 23rd in The Open on his last start three weeks ago.

Westwood was a distant second behind Louis Oosthuizen at St Andrews, but went into the championship with a ruptured calf muscle.

He flew to the States from Manchester after what his website called a "busy break" - a short holiday in Cannes, visiting the Lee Westwood Golf Academies and officially unveiling the revamped Kilton Forest Golf Club in his home town of Worksop.

Australian Stuart Appleby, meanwhile, qualified for the WGC – Bridgestone Invitational by winning the Greenbrier Classic with an astonishing closing 59 - only the fifth in US PGA Tour history, but the second in the last four weeks.

And runner-up Jeff Overton, up from tenth to fourth on the American Ryder Cup table with just two qualifying events left for them, plays in Akron as well after climbing into the world's top 50.