Scottie Scheffler delivered a storming finish to his third round at the Tour Championship to carry a six-shot lead into the final 18 holes at East Lake.
After nearby lightning strikes caused play to be suspended on Saturday, world number one Scheffler returned re-energised on Sunday morning to grasp control of the leaderboard.
Xander Schauffele had pulled to just one stroke behind Scheffler, but the leader made his big move with four birdies in his closing six holes when play resumed.
Scheffler had been level par for his third round through 12 holes, which is the point at which he had to leave the course the previous day, but Sunday's surge carried the 26-year-old to a 66 and 23 under par for the tournament.
Playing partner Schauffele could not muster a response to Scheffler, and he made bogey at the long par-four 14th to see the gap widen, having to settle for a level-par 70.
Rory McIlroy birdied 17 and 18 to complete a seven-under 63 and join Schauffele in a tie for second place through 54 holes, on 17 under par, with South Korea's Im Sung-jae and American Patrick Cantlay one shot further back.
The final event of the FedEx Cup sees the winner of the Tour Championship pocket staggering prize money of $18million, with the runner-up taking $6.5million.
Scheffler began the tournament on 10 under, under the unusual format that saw a staggered start based on performances in the previous FedEx Cup events.
He was the leader of the series standings so was duly rewarded, with second-placed Cantlay starting the week on eight under.