Overnight co-leader Jason Day has dropped into a tie for third after 54 holes of the PGA Tour’s Deutsche Bank Championship at TPC Boston.

Day shot a two-under-par round to be two shots behind leader Russell Henley who fired six under on Sunday to sit at 12-under-par for the tournament and one stroke clear of fellow American Billy Horschel.

World No.1 Rory McIlroy, the 2012 winner, and Chris Kirk both fired seven-under 64s to jump into a share of third place with Day at 10-under-par 203.

Former tournament winner Webb Simpson moved into sixth place at nine under behind a third-round 68.

Ryan Palmer, who shared the second-round lead with Day, posted his second straight even-par 71, dropping into a tie for seventh at eight-under 205.

Palmer was joined there by Kevin Streelman (65), South Korea’s Noh Seung-Yul (68) and American Keegan Bradley (69).