England's Ian Poulter and Andy Sullivan earned a four-way share of the lead after the opening round of the World Tour Championship in Dubai.
They shot a six-under-par 66 alongside German Martin Kaymer and Australian Marcus Fraser.
Italian Francesco Molinari was one shot off the pace, while Northern Ireland's Rory McIlroy carded a four-under 68.
Poulter, who has not won a Tour event for three years, has been struggling with a foot injury.
"I was kind of sick of taking painkillers so I had a cortisone injection," he said.
"It's still a little sore this morning. My back's a little sore. My hand's a little sore. That's what you get when you play five weeks in a row."
Englishmen Danny Willett, Chris Wood and Matthew Fitzpatrick were among an eight-strong group featuring McIlroy on four under.
The tournament at the Jumeirah Golf Estates is the £5.2m finale to the European season.
World number three McIlroy leads the Race to Dubai standings ahead of Willett, although seven players could still take the title.
Sullivan, 28, whose three career Tour wins have come this season, was playing alongside two-time major winner Kaymer.
Cheered on by 30 fans from his club in Nuneaton, Sullivan carded an eagle, five birdies and a bogey.
"Every putt that went in they were really cheering and it's a big plus," he said.
"They've been to Wentworth, Woburn and Portugal this year and have been planning this trip since the middle of the year, dying to get out of the cold at home."