Danny Willett was knocked off top spot in the Race To Dubai rankings after a disastrous outing at the WGC HSBC Champions in Shanghai.
Willett finished third last in the tournament after carding 14 over par over four rounds.
The result saw him overtaken by Swede Henrik Stenson in the Race To Dubai with just three events remaining.
Stenson finished in a tie for second in Shanghai to snatch top spot.
Willett has led the order of merit for most of the season after winning the third event of the year, the Dubai Desert Classic and following up with his triumph at the Masters in April.
But he faces losing his grip on the title at the death, just as he did last season as Rory McIlroy claimed the crown in the final event.
Fellow Sheffield golfer Matt Fitzpatrick fared much better in China, securing a 16th placed finished after a final round 65 left him on -7 for the weekend.