Controversial United States golfer Patrick Reed is dialled in on the final day of the Presidents Cup, despite the absence of his caddie in Melbourne.

Reed teed off in Sunday's singles without usual right-hand man Kessler Karain, who was suspended by the PGA Tour following a fan altercation on Saturday.

But after a forgettable first three days amid cheating allegations and heckles at Royal Melbourne Golf Club, 2018 Masters champion Reed is finally enjoying some success.

Reed - coming off three straight defeats - birdied five of his opening seven holes to race out to a commanding 6up lead against International opponent C.T. Pan.

American Reed birdied his first three holes and the sixth as the USA - trailing 10-8 at the start of play - eye their eighth consecutive Presidents Cup.

Kevin Kirk is caddying for Reed, who has endured a tough week at the 13th Presidents Cup.

Reed has been public enemy number one in Australia after his two-stroke penalty during last week's Hero World Challenge in the Bahamas.

Already a maligned figure on the PGA Tour, Reed was penalised for improving his lie in the bunker, hitting the sand twice during his practice swings, sparking controversy and claims of cheating.

Booed on day one, Reed taunted the Melbourne crowd on Friday by mimicking a shovelling motion, before tensions boiled over on Saturday.

Karain clashed with a fan after he had "had enough" of the heckling of Reed, before the Tour ultimately intervened.