Rory McIlroy started his third round with two bogeys but recovered to shoot two rounds under 70
Rory McIlroy and Tommy Fleetwood, trail leader, all at once, Rahm, will qualify for the last round of the Players Championship at Sawgrass.
McIlroy of Northern Ireland and Fleetwood of England recovered in the third round after a poor start to the match and managed two shots under par 70.
The Spaniard Rahm has four birdies and an eagle at the back of his 64 years.
Jason Day (68) is 12 years old, Abraham Ancer (70) is 11 years old and world number one Dustin Johnson (69) is 10 years old.
Johnson is joined 10 times by his American compatriots Ollie Schniederjans (65), Brandt Snedeker (65), Keegan Bradley (68), Brian Harman (71) and Jim Furyk (71).
McIlroy is looking for his first tournament win for more than a year, while Fleetwood has not won in the United States yet.
Fleetwood told Sky Sports: "I had some very quick shots and I did an absolute hash of the first hole after a good start, which was followed by poor shots at four, six. and seven.
"It was a real test of courage and mental strength, I succeeded and I did very good things at the back nine.I am really delighted with the way that this it's over. "
McIlroy told NBC Sports: "Going below average was a good effort after two early bogeys.
"Once tied, I felt I was in the ground, I was not driving well and I'm going to work on it now on the shooting range."
Rain and strong winds are forecast for Sunday's final round in Florida.