Spieth, 23, bogeyed three holes and was involved in huge drama at the 13th.

The American appeared to have steadied the ship with three pars to start the back nine, but dropped out of the lead in extraordinary circumstances on the 13th.

After a wild drive into the rough, Spieth took a penalty for an unplayable lie, entitling him to go back in a straight line as far as he liked to find a favourable place to drop.

That happened to be the practice range between the 13th and 15th holes and specifically a truck belonging to one of the equipment manufacturers, from where Spieth could then get a free drop away from a temporary immovable obstruction.

Around 20 minutes after finding his ball, the 23-year-old eventually hit his third shot short of the green, chipped to seven feet and holed out for a remarkable bogey.

That gave Matt Kuchar the outright lead, but that only lasted a matter of minutes as Spieth almost holed his tee shot on the par-three 14th and holed from three feet for birdie.