Akron - Masters and US Open champion Jordan Spieth will be seeking to unseat Rory McIlroy as world No 1 here on Thursday when he tees off in the WGC-Bridgestone Invitational.
Spieth, still smarting from his agonising failure to win the British Open at St Andrews last month, headlines the small-field, no-cut tournament which includes 48 of the top 50 players in the world.
"It would be a dream come true," Spieth said on Wednesday of the number-one ranking. "At the beginning of the year I wanted to work my way up the world rankings. I didn't think I could be in this position or have this opportunity.
"I feel blessed at the way this year has gone... Obviously we all want Rory back ASAP. It would be really incredible if at the end of the week I was holding the trophy and having that position moving forward."
The two most recent WGC-Bridgestone winners, defending champion McIlroy and Tiger Woods, are noticeably absent but there will still be plenty of firepower at the event, the final tune-up before the PGA Championship at Whistling Straits.
McIlroy, who held off Sergio Garcia to win last year, suffered a torn ankle ligament in July and eight-time Bridgestone winner Woods wasn't invited. Woods won in 1999, 2000, 2001, 2005, 2006, 2007, 2009 and 2013.
Spieth will have a host of challengers standing in his way at the Firestone Country Club, including red-hot Australian Jason Day, fellow American Dustin Johnson, Adam Scott of Australia, England's Justin Rose and Rickie Fowler, of the US.
Spieth, 22, leads the PGA Tour with four victories this season. In his last outing he was in contention to claim his third straight major before finishing in a tie for fourth at the Open Championship at St. Andrews.
He ended up one shot shy of getting in a playoff with winner Zach Johnson so he comes into the Bridgestone with a chip on his shoulder.
"I'm hoping to prove that I've kind of got a little bit of revenge that I need to get out from having control of the Open Championship with two holes to go and not closing it out," Spieth said.
"That leaves a bad taste in my mouth, not because of the third in a row, but strictly because you don't get many opportunities to contend in a major, in an Open at St. Andrews, in your life.
"It was a tough feeling on that flight home, especially with Zach and the (Claret) Jug there. I wish that it was in my possession and not his."
Spieth finished 49th and failed to break par in any of his rounds in his Bridgestone debut last year.
"It's a big, meaty course," he said. "I struggled with it last year. It's going to take some really strong driving of the golf ball."
Day, who is coming off his second win this season at the Canadian Open, returns to the Bridgestone where he withdrew two holes into the third round last year with dizziness.
He since was diagnosed with vertigo which flared up again at this year's US Open in June.
"It's tough because vertigo, I can't get rid of, and it will come back whenever it wants to. So I'm just trying to manage it the best I can," Day said.
Johnson is hoping to add to a strong season that includes seven top-10 finishes and his last two victories came in World Golf Championships - the 2013 HSBC Champions in China and the Cadillac Championship at Doral in March.
He will try to become the third player to claim two WGC titles in one season.