PARIS (AFP) - Japan's Kei Nishikori admitted Saturday's rain interruption was crucial after fighting off a fierce five-set challenge from rising South Korean talent Chung Hyeon to reach the French Open last 16.
Eighth seed Nishikori led the all-Asian tennis duel two sets to one but trailed by a double break at 0-3 down in the fourth set when rain halted play.
Chung forced the contest into a deciding set as play resumed on Sunday, but the world No. 67 double-faulted on match point to hand Nishikori a 7-5, 6-4, 6-7 (4-7), 0-6, 6-4 victory.
"I think the rain helped me a lot, because I was really down in the fourth set and mentally I wasn't ready," said Nishikori, who received a code violation Saturday after smashing a racquet in frustration.
"I knew I had to change something to beat him today, so I think I made some adjustments to make little better than yesterday.
"Mentally I was a little more fresh, and physically, too, little more have energy on my legs. That helps me a lot."
In women's play, Caroline Wozniacki reached the quarter-finals for the first time in seven years with a 6-1, 4-6, 6-2 win over 2009 champion Svetlana Kuznetsova.
The Danish 11th seed, who made her only other last-eight appearance in Paris in 2010, faces either Australia's Samantha Stosur or Jelena Ostapenko of Latvia for a semi-final place.
"Svetlana's a great player, especially on clay so I knew it wouldn't be easy," said the 26-year-old after her eighth win in 14 meetings against the Russian. Sunday's clash was their first on clay.
"I played a great first set but I still knew I had to stay cool and aggressive."
Nishikori, meanwhile, will play unseeded Spaniard Fernando Verdasco, conqueror of Alexander Zverev in the opening round, as he tries to reach the quarter-finals for the second time in three years.
It was the first third-round meeting between two Asian players at Roland Garros, with 21-year-old Chung conceding that Saturday's weather delay arrived at an inopportune time.
"If I play yesterday, maybe better for me," said Chung, when asked if he would have preferred to stay out on court.
But he was keen remain upbeat despite an agonising defeat.
"It's great experience in Paris. I make third round first time in Grand Slam. And maybe I have more experience and I have to enjoy. I'm looking forward to another Grand Slam," he said.
"It was great honour to play with Kei. He's a great player in the world. And today was tough match against Kei.
"It was really fast and good stroke-making. But I tried my best and maybe I'm waiting for another day."
Chung fell short in his bid to become just the second Korean player after Lee Hyung Taik to reach the last 16 of a Major.
But he hopes his performances in Paris can inspire more interest back home.
"In my country tennis is not popular yet. So I want to make more popular in Korea," he said.
"I want to break my highest ranking. So maybe I want to make top 50 first, and then maybe if I make top 50 then change (my goal) again."