Novak Djokovic and Rafael Nadal can set up a blockbuster French Open semi-final clash on Wednesday as both men close in on rewriting the tennis record books.
World number one Djokovic, the 2016 champion, and an 18-time Grand Slam title winner, faces Italian ninth seed Matteo Berrettini.
Victory would put him into the semi-finals in Paris for the 11th time and two wins away from becoming only the third man in history to win all four majors twice.
Djokovic had to dig deep against another Italian to guarantee his passage to the 15th quarter-final in Paris.
He was given a huge scare in the fourth round when 19-year-old Lorenzo Musetti raced into a two sets lead before running out of steam and quitting in the fifth set.
"Berrettini has a big serve, big forehand. Two big weapons. He's in form," said Djokovic who defeated the Italian in their only previous meeting at the 2019 ATP Tour finals.
Victory on Wednesday would put Djokovic into a 40th Grand Slam semi-final.
Berrettini has been solid on clay this year, finishing runner-up in Belgrade and Madrid but the highest-ranked player he has faced in Paris is world number 91 Kwon Soon-woo, his third round opponent.
He also arrives fresher than Djokovic has been given a walkover into the last eight when Roger Federer withdrew from the tournament.
Nadal, who is bidding to capture a 14th Roland Garros and record-setting 21st major, is on a run of 35 consecutive winning sets at the French Open.
The reigning champion meets Argentine 10th seed, Diego Schwartzman.
Nadal boasts a 10-1 record over Schwartzman, including a straight-sets win in the semi-finals of last year's delayed French Open.
A victory for Nadal would put him into the last four at a Slam for the 35th time.