Rory McIlroy lost 10lbs due to illness in the days before his four under opening round at the HSBC Champions on Thursday, but had something else to worry about as Danny Willett made a flying start in Shanghai.
Willett is almost 400,000 points behind McIlroy, who was suffering with a bad dose of food poisoning earlier in the week, in the Race to Dubai, but each of the Final Series events offers 1.3 million points to the winner.
Willett is playing in the remaining three in an attempt to finish the season as European number one for the first time.
The 28-year-old from Sheffield started from the tenth at Sheshan International in China and covered the back nine in 32.
He then picked up further shots on the second, third, seventh and eighth before dropping his only shot of the day on the ninth.
That gave the English man an opening round seven-under-par 65, one shot behind clubhouse leader Branden Grace.
This was also good enough to open up a three shot lead on McIlroy, who undid the good work of a six-birdie round with a double bogey six on the par four 15th.
McIlroy had recovered sufficiently from at earlier illness to take part in the final World Golf Championship event of the year, a tournament where he has never finished outside the top six in four previous appearances.
"It was probably a little better than I was expecting out there to be honest," said McIlroy.
"When I was hitting balls this morning on the range I had not been out of bed for basically 48 hours, so I was really stiff. I needed to loosen up quite a lot, but when I got out there I felt pretty good.
"I've lost 10lb since being here. I can't remember the last time I was this light. But hopefully (if I have) a couple of good meals over the next couple days and rehydrate I'll be feeling a lot better.
"I'm looking forward to a good dinner tonight but hopefully it will stay inside my body."
The tournament is being led by South African Grace, who didn’t drop a shot as he fired a sparkling 63 to sit on nine under.
This puts him one stroke ahead of Kevin Kisner of America, Australian Steven Bowditch and Thorbjon Olesen from Denmark.
World number two Jordan Spieth, who can reclaim top spot in the rankings from the absent Jason Day with a top-10 finish, finished at four under alongside number three ranked McIlroy.
It was a tough day at the office for Shane Lowry, who completed his first 18 holes near the foot of the leaderboard on two over
Willett (pictured above) was disappointed to bogey his final hole but delighted to still be challenging McIlroy for the Race to Dubai after two wins this season and a share of sixth place in the Open at St Andrews.
"We've not dropped out of the top two on the Order of Merit all year," said Willett, who beat McIlroy in the first round of the Amateur Championship in 2007 and played on the same Walker Cup team a few months later.
"It's been nice to be up there. You have to put yourself somewhere near and see what happens.
"I don't think he's playing next week and if you can be within touching distance going into Dubai, Dubai could be pretty interesting."
