London, Napa, United States: Jason Day has replaced Jordan Spieth as world number one in the latest golf rankings released on Monday.
The Australian, who won his first major title at the PGA Championship in August, takes the top spot for the second time in his career.
He moved ahead of Spieth on September 21, but lasted just a week as the American won the Tour Championship to regain top spot.
Neither player was in action last week, which ensured that Day would edge ahead based on the rankings formula with 12.42 points average to 12.40 for Spieth.
Former world number one Rory McIlroy remained in third place on 10.92 points with the new “Big Three” of golf well ahead of the rest of the pack led by Bubba Watson.
Spieth won the Masters and US Open this year before finishing tied for fourth at the British Open and second behind Day at the PGA Championship.
Day has won six tournaments during the year, including four victories in six starts around the PGA Championship.
McIlroy lost the top ranking to Spieth earlier this year and then he missed the defence of his British Open crown at St Andrews when he injured an ankle playing football.
In Napa, United States, rookie Emiliano Grillo sank a birdie putt on the second play-off hole to outlast Kevin Na and claim his first USPGA Tour title in the season-opening Frys.com Open on Sunday.
The 23-year-old from Argentina, who earned his PGA Tour card just two weeks ago by winning the Web.com Tour Championship, fired a three-under 69 — draining a long birdie putt on the 72nd hole to set up the playoff.
Grillo, already being touted as rookie of the year contender, won in his first tournament as a card-carrying tour member. His previous appearances on the US Tour came through sponsor’s invitations.
“I was just really focused on my putt and I hit a great putt to win,” said Grillo, who had showed he could compete on the big stage before, losing in a playoff to Alex Cejka of Germany in the Puerto Rico Open and tying for 10th in the Barbasol Championship.
Grillo had a three-foot putt for the win on the first playoff hole but his ball just caught the left edge and stayed out.
“I hit this one good. I don’t know what happened,” he said. “My caddie asked me on the next tee ‘Are you OK?’ I said I am.”
He and Na both parred the hole so that sent them back to the tee off the par-five 18th again to try and decided the winner.
American Na hit a nice tee shot, but he chose to go with a driver off the fairway and hooked it behind a tree. That left him with a tricky approach shot from the rough.
