Paris - Andy Murray downed longtime rival Juan Martin del Potro to reach the Roland Garros last 16 Saturday while French hopes were overshadowed by a bitter feud between two of their top stars.
World number one Murray triumphed 7-6 (10/8), 7-5, 6-0 for his seventh win in 10 meetings with Del Potro whose challenge fizzled out after squandering four set points in the 87-minute opener.
Murray, the runner-up to Novak Djokovic in 2016, will next face either John Isner of the United States or Russia's Karen Khachanov.
"I expected a very tough match. Whoever won that first set would have the momemtum as it would have been very difficult to come back in these heavy, slow conditions," said Murray.
"He was playing much better than me in the first set. He had chances in the first set, he double faulted on set point."
In a titanic first set, Del Potro wasted four set points then saved two before Murray pounced for the opener when the Argentine star narrowly miscued.
The 28-year-old slumped over the net and stayed bent over during most of the changeover to catch his breath.
Del Potro, playing in Paris for the first time in five years after a series of wrist injuries, was quickly a break down in the second set.
He retrieved it when Murray served for the set in the 10th game before handing the advantage straight back.
Murray seized his lifeline, a fourth ace giving him a two-set lead.
Weary Del Potro, who had already summoned the doctor early in the second set, knew his challenge was over and he managed just 11 points in the third set.
Former US Open champion Marin Cilic continued his smooth progress seeing off Feliciano Lopez, who was limited by a neck injury, 6-1, 6-3, 6-3.
Croatian seventh seed Cilic will next meet South Africa's Kevin Anderson who matched his best run at Roland Garros with a five-set win over Britain's Kyle Edmund.
Anderson twice recovered from a set down to advance 6-7 (6/8), 7-6 (7/4), 5-7, 6-1, 6-4 in just under four hours in a duel between two players born in Johannesburg.