Norway's Viktor Hovland and American Ryan Gerard are locked in a tie for the lead at 10 under after round two of the Tour Championship in Atlanta.
Hovland carded a four-under 66, finishing with a birdie on the final hole to join Gerard who had set the clubhouse pace with a five-under 65 earlier in the day.
Gerard's performance included a memorable stroke as he rolled in a stunning 78-foot birdie putt that covered the entire length of the seventh green.
World number one Scottie Scheffler fired a six-under 67 to move into second position, overcoming two bogeys he took early in his round.
Cameron Young, the March winner of the Players Championship, is also at eight under following a scintillating 62 that featured seven birdies and an eagle on the par-five 18th hole.
Justin Rose played superbly with a bogey-free 65, placing him three strokes adrift at seven under overall in contention for the $10m (£7.4m) Sunday prize.
Rory McIlroy found himself two-over par after four holes despite opening with a birdie, his frustration visible on the third when he missed the green and twice failed to chip from the same spot.
McIlroy eventually made two birdies in the final three holes but sits tied for 23rd at three under, needing significant improvement on Saturday to stay relevant.
Robert MacIntyre recorded a forgettable six-over 76 after finding water off the tee on the par-three 15th and taking three consecutive bogeys before a double bogey.
The 30-year-old from Scotland was one of only three players to finish round two over par, joining Min Woo Lee and Xander Schauffele in that group.
Hovland's victory in the Fedex Cup last year has not shielded him from competition as he seeks his first major title at this event.
The field remains tight with multiple contenders within striking distance as the tournament moves into its concluding phase.
No further details were provided regarding specific future outcomes or guaranteed progression for any player beyond the current leaderboard status.