|Tour Championship third-round leaderboard|
|-12 P Casey (Eng); -10 K Kisner (US), X Schauffele (US); -7 B Koepka (US), P Reed (US), J Thomas (US)|
|Selected others:-6 J Rahm (US); -4 J Spieth (US), D Johnson (US); +1 M Leishman (Aus)|
England's Paul Casey boosted his hopes of winning the FedEx Cup and a $10m (£7.4m) bonus by moving into the lead in the season-ending Tour Championship.
Joint overnight leader Casey, 40, shot a five-under-par 65 to move to 12 under after three rounds in Atlanta.
He is two shots ahead of Americans Kevin Kisner and Xander Schauffele.
If Casey - 10th in the FedEx standings - wins the tournament, he could take the FedEx title depending on where higher-ranked players finish
"I want the win. I want my name on the trophy at East Lake," said Casey, whose daughter Astaria was born two weeks ago but he has not met her.
He told Sky Sports: "The cool thing is that I'll be playing in the final group with Kisner and we've both just had children. My little girl was born on September 11 and his boy I think a couple of days prior to that.
"I won a week after Lex (his son) was born at the KLM Open so, although this tournament is the most important thing tomorrow, there are more important things away from the course."
Any of the 30 players in the tour Championship can theoretically win the FedEx Cup, but only those in the top five in the standings are assured of doing so with victory.
Open champion Jordan Spieth began the week with a 200-point lead over Justin Thomas, with world number one Dustin Johnson, Marc Leishman and Jon Rahm the other players in control of their own destiny.
Thomas, Casey's playing partner, is five shots behind after shooting a 70, with Rahm a shot further back, Spieth and Johnson eight shots off the lead and Leishman on one over.
Casey, who has not won a PGA Tour title since 2009, said: "My last round here last year was a 64 and I'd take a 64 on Sunday."
He carded birdies on the third and fifth, an eagle on the sixth and another birdie on the seventh after almost holing his approach.
But Casey failed to get up and down from greenside bunkers on the next two holes, while Kisner birdied the 13th and chipped in for another on the next.
A birdie on the 11th edged Casey back in front and another from 40 feet on the 17th extended his advantage.