Donald and Casey share the early lead after rounds of 66

Luke Donald and Paul Casey are even closer to a possible £7.2m jackpot – the richest prize in golf – this weekend after making superb starts to the Tour Championship in Atlanta yesterday.

The two English players both kicked off the final leg of the FedEx Cup play-off series with four under par rounds of 66 to share the lead with Australian Geoff Ogilvy.

Donald, of course, is bound for Celtic Manor and the Ryder Cup next week, but world No 7 Casey was controversially left out by Colin Montgomerie and has let his golf do his talking ever since.

Runner-up in the BMW Championship in Chicago two weeks ago –he led by two with six to play and let it slip – Casey is fifth in the cup standings and victory in the tournament on Sunday will guarantee him the near £6.4m that goes to the overall winner. Donald, meanwhile, needs to win and hope that current top two Matt Kuchar and Dustin Johnson are not second to him. And both had disappointing opening rounds.

"It's early days," said the 32-year-old after grabbing six birdies. "Anything can happen – but it's nice to position yourself. The course is firm and fast and that makes it play difficult, but if I could do the same the next three days I would take it right now."

Casey was in the water on the short sixth, but it was his only mistake. He also turned in 33 and then picked up more shots on the 10th and long 15th. Defending champion Phil Mickelson had two eagles on the back nine, but still had to settle for a one under 69. Needing a top-two finish to take over as world No 1 from Tiger Woods, Mickelson sank a 115-yard pitch for a two at the 12th and then rolled in a 14-foot putt three holes later for his second eagle.

Meanwhile Padraig Harrington seven birdies and yet still found himself seven shots off the lead after the opening day of the Vivendi Cup in Paris yesterday.

The only member of next week's Ryder Cup side in the field after the withdrawal of the Swede Peter Hanson with a chest infection, the Irishman signed for a four-under-par 68. But an hour later Swede Johan Edfors completed a 61 which equalled the low round of the European Tour season and knocked two strokes off his best score on the circuit.