Ernie Els has carded a third-round 65 to remain on track for a first victory in three years at the Quicken Loans National.
The four-time Major winner closed to within two shots of current leader Billy Hurley III heading into Sunday's final round in Bethesda.
Els registered three birdies in a row, starting on the sixth, before a double eagle on the 12th saw him further close the gap at the Congressional Country Club.
Leader Hurley did just about enough to remain atop the leaderboard with his round of 67, leaving him on 15-under-par overnight and ahead of the chasing pack.
While Els provides Hurley's sternest challenge, Spaniard Jon Rahm (12-under) and American duo Bill Haas and Webb Simpson (both 10-under) are still within touching distance.
The four highest finishers at this event to have not already qualified for next month's Open Championship will earn a place in the illustrious competition.
