* Croatian has yet to drop a set in tournament
* Cilic equals his best performance at French Open (Updates with details, quotes)
By Karolos Grohmann
PARIS, June 3 (Reuters) - Seventh seed Marin Cilic established himself as a contender for the French Open title after sweeping past Feliciano Lopez 6-1 6-3 6-3 on Saturday to reach the last 16 without dropping a set.
The 2014 U.S. Open winner, who warmed up for the year’s second grand slam by capturing his first claycourt title in five years in Istanbul last month, delivered a near-perfect performance to equal his best-ever showing in Paris.
He whipped 31 winners past the helpless Spaniard, who at 35 was the oldest player left in the draw and whose big serve lost some of its edge due to humid and cloudy conditions.
“My return was working extremely well. I am very pleased with that,” said Cilic, who reached 100 Tour-level victories on clay. “The heavier conditions favoured me a bit... because he has a huge serve.”
Left-hander Lopez, who twice needed treatment for a sore neck, was broken seven times as Cilic attacked his serve at every opportunity and kept the Spaniard pinned to the baseline.
The 28-year-old Croatian notched his first win on clay over his opponent when he fired his eighth ace past him to set up a round of 16 clash with either Britain’s Kyle Edmund or Kevin Anderson of South Africa.
“To finish matches as quickly as possible is never easy. I am extremely satisfied, especially with how I have been playing the last couple of months,” Cilic said. “This week I played great and I hope to continue.” (Editing by Nick Mulvenney and Pritha Sarkar)