Barcelona - Andy Murray made it 11 wins in 11 meetings with Feliciano Lopez while Rafael Nadal racked up a 50th win in Barcelona as the two Grand Slam heavyweights reached the last eight on Thursday.
World number one Murray, playing his first match of the week after Australia's Bernard Tomic scratched from their scheduled opener with injury, downed Lopez 6-4, 6-4.
His win in one hour and 49 minutes extended his perfect record over the left-handed Lopez to 11-0, a run which now includes two wins on clay.
Murray will next face 10th seed Albert Ramos-Vinolas, the player who shocked him in the Monte Carlo Masters third round last week.
Ramos-Vinolas defeated sixth seeded compatriot Roberto Bautista Agut 6-2, 3-6, 6-4.
"I was happy to play today. It was nice to get through and have another match tomorrow," said Murray.
Nadal moved closer to a 10th Barcelona title when he cruised past South Africa's Kevin Anderson 6-3, 6-4 for a 50th victory in the Spanish city.
"It wasn't a day where I took a lot of free points because the court was very heavy. But I was serving well, at a good speed and changing directions well," said Nadal, playing on a court named after him.
"I had the chance to hit my forehand after my serve and take control of the rallies, so I'm very happy with how I played."
Third seed Nadal, fresh from a 10th Monte Carlo triumph at the weekend, next faces South Korean qualifier Hyeon Chung who stunned German eighth seed Alexander Zverev 6-1, 6-4.
The 20-year-old Korean, who has yet to drop a set this week, is through to his first quarter-final since Houston in April 2016.
Japanese lucky loser Yuichi Sugita reached the last eight with a 6-3, 6-3 win over seventh seed Pablo Carreno Busta of Spain.
Having already earned the biggest victory of his career on Tuesday by defeating France's world number 23 Richard Gasquet, Sugita scored a new career-best by breaking the Spaniard three times.
"It was my best win. It's unbelievable," said 28-year-old Sugita. "This was very important for my life, so I'm really glad about it."
Sugita next faces Austrian fourth seed Dominic Thiem, a 7-6 (7/5), 6-2 winner over Dan Evans of Britain.
Results from the ATP Barcelona Open on Thursday (x denotes seeding):
Andy Murray (GBR x1) bt Feliciano Lopez (ESP x16) 6-4, 6-4
Albert Ramos Vinalos (ESP x10) bt Roberto Bautista (ESP x6) 6-2, 3-6, 6-4
Dominic Thiem (AUT x4) bt Daniel Evans (GBR) 7-6 (7/5), 6-2
Yuichi Sugita (JPN) bt Pablo Carreo-Busta (ESP x7) 6-3, 6-3
Hyeon Chung (KOR) bt Alexander Zverev (GER x8) 6-1, 6-4
Rafael Nadal (ESP x3) bt Kevin Anderson (RSA) 6-3, 6-4
Karen Khachanov (RUS) bt David Goffin (BEL x5) 6-7 (7/9), 6-3, 6-4
Horacio Zeballos (ARG) bt Benot Paire (FRA) 6-4, 3-6, 7-6 (7/3)