Defending champion Li Haotong fell foul of a new golf rule and incurred a costly two-stroke penalty at the final hole of the Omega Dubai Desert Classic on Sunday.

Caddies are no longer allowed to stand directly behind their player and help with alignment, a rule that was expected have more effect on women's golf, where it had become a common occurrence.

The new rule, one of a raft of changes introduced on Jan. 1, states: "Once the player begins taking a stance for the stroke, and until the stroke is made, the player’s caddie must not deliberately stand on or close to an extension of the line of play behind the ball for any reason."

Li had started to take his stance for a putt before his caddie, who had been standing behind him, moved to the side.

Though the caddie had moved away before Li completed his stance, European Tour officials still decided the Chinese player had breached the rule.

The penalty turned a birdie into a bogey at the par-five 18th.

Instead of finishing equal third at 16 under par, Li dropped into a tie for 12th. The tournament was won by American Bryson DeChambeau.