Having become the first player to start a PGA Tour event with an advantage, Justin Thomas saw his two-stroke lead eroded after day one at the Tour Championship in Atlanta. Under the new FedEx Cup playoffs format, the American started the tournament on 10-under par having reached the final event of the season as the leader in the FedEx series.

The 30-man field at East Lake were then ‘handicapped’ down to level-par but, after 18 holes, Thomas has been joined by compatriots Brooks Koepka and Xander Schauffele on 10-under par, with Rory McIlroy a single shot behind the pacesetting trio. Patrick Cantlay and Matt Kuchar are another shot back on eight-under par, with Hideki Matsuyama next and then Patrick Reed, Jon Rahm and Paul Casey all on six-under.

After day one, 10 players are within four strokes of the lead, ensuring the new format met with approval on most fronts. Thomas (70) needed a closing birdie at the par-five 18th to stay in a share of the lead after a double-bogey at the par-three 15th derailed him, alongside a couple of missed putts from close range.

Schauffele (64) shot the round of the day to pick up six shots and move into the clubhouse lead before he was joined by world number one Koepka (67), while McIlroy (66) missed a 6ft birdie chance on the final hole that would have tied him for the lead. Starting out on Thursday there were just five players within five shots of the lead but, after just one round, there are now a dozen within range.

Koepka is the new favourite to win the Tour Championship at 3.60 ahead of McIlroy at 5.00, with Thomas 5.25 following his lacklustre opening and co-leader Schauffele 6.50.