A frustrated Danny Willett lost ground on the leaders on day two of the Turkish Airlines Open as he looks to end the season as European number one for the first time.

Willett was encouraged by an opening 69 in Antalya after struggling for form recently, the Masters champion describing his performance in last week’s WGC-HSBC Champions as the worst of his career.

But, despite hitting every fairway on the front nine of his second round at Regnum Carya Golf & Spa Resort on Friday, the 29-year-old could only complete them in one over to drop back to one under for the £5.7million event.

Willett, who needs to finish fifth or better to reclaim top spot in the Race to Dubai from Henrik Stenson, missed birdie chances on each of the first five holes before failing to get up and down from just left of the sixth green.

The world number 10 then hit a tree with his second shot on the par-five seventh, but produced a brilliant approach with a fairway wood and narrowly failed to convert the birdie attempt from 25 feet.

Further birdie opportunities went begging on the eighth and ninth to leave Willett six shots off the lead shared by Denmark’s Thorbjorn Olesen and Spain’s Adrian Otaegui.

Overnight leader George Coetzee was a shot behind after a bogey on the third, the South African joined by Joakim Lagergren, Matteo Manassero and Jorge Campillo on six under par.

While Willett was struggling to find any birdies, Otaegui had started his round – from the 11th due to the course layout – with five in a row before collecting another on the 18th.

Olesen, who carded a flawless 65 on Thursday, had started from the first and birdies there and on the sixth took the Dane into the outright lead on eight under.

Manassero, who won four times on the European Tour by the age of 20 but had slumped to 596th in the world before finishing third in the Scottish Open in July, was seven under after three birdies and one bogey in his first six holes.