Jason will have his Day at number one, says Peter Thomson

Melbourne: Jason Day`s bid for the world number one ranking stalled at the Deutsche Bank Championship but it should only be a matter of time before the Australian scales the mountain, according to five-times British Open champion Peter Thomson.

Victory at Deutsche Bank would have handed Day the top ranking but the fatigued 27-year-old hit the wall at TPC Boston and finished in a tie for 12th, nine strokes behind American winner Rickie Fowler.

Day is still top of the FedExCup standings after winning the opening Barclays tournament but will stay world number three.

American Jordan Spieth takes back top spot from Rory McIlroy but only fleetingly, with the Northern Irishman to be restored to number one heading into the BMW Championship in two weeks` time due to the vagaries of the rolling two-year rankings system.

Australian Thomson, who won his five Open crowns from 1954-1965, felt Day was primed to take the number one spot but holding onto it against the likes of fellow 20-somethings McIlroy and Spieth would be a challenge.

"He`ll have his turn at being number one and then probably someone else will take over for a while," the 86-year-old World Golf Hall of Famer told Reuters by telephone.

"There`s a category of people in the top echelon. He`s one of them.

"We had a solitary fellow when (Tiger) Woods was going at his best. It`s a group we`re looking at now.

"They seem to be very friendly to each other. They all have similar styles."

Day rode a hot streak in the leadup to the Deutsche Bank Championship, piling up wins at the Canadian Open, PGA Championship and The Barclays.

But he shuddered to a halt with a third-round 73 at TPC Boston and said he was "cooked" after signing off with a 69 on Monday.

After winning the Masters and the U.S. Open, Spieth has also struggled since his runner-up finish behind Day at the PGA Championship and missed the cut at the Deutsche Bank.

McIlroy is also no stranger to sudden lapses in form and after winning his second major at the 2012 PGA Championship, toiled through a tough 2013 before roaring back with another two major wins last year.

Thomson felt the merry-go-round at the top could continue for some time and didn`t feel confident that any of the pack could sustain a dynasty like 14-times major champion Woods, who spent a record 281 consecutive weeks at number one.

He also felt Day was at peril of a form dip after the emotion of his breakthrough win at the PGA Championship following a number of near-misses at the majors.

"I think there`ll be a variety of (major) winners from here," Thomson said. "I should think now that (Day`s) won one of the majors, he might go backwards a bit for a while."

The club of youngsters at the top of the golfing world might have room for another, Thomson added.

He was impressed with 26-year-old Fowler`s performance at the Deutsche Bank Championship.

Fowler`s one-stroke win after out-duelling Swede Henrik Stenson lifted him to world number five and third on the FedExCup standings.

"I like his style and his attitude, I think he`s very good," Thomson said. "He`s going to be getting his share."