BARCELONA, Spain (AP) -- Defending champion Rafael Nadal defeated Kevin Anderson 6-3, 6-4 to reach the quarterfinals of the Barcelona Open while Andy Murray struggled to join him on Thursday.
Murray had his hands full getting past Feliciano Lopez 6-4, 6-4.
Nadal converted a break point in each set to secure his seventh straight clay-court victory.
"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," Nadal said. "I had the chance to hit my forehand after my serve and take control of the rallies."
Nadal, a nine-time champion in Barcelona, will next face qualifier Hyeon Chung of South Korea, who defeated eighth-seeded Alexander Zverev of Germany 6-1, 6-4.
The fifth-ranked Nadal is coming off his 10th title at the Monte Carlo Masters.
The top-ranked Murray took nearly two hours to close out 40th-ranked Lopez.
Murray will play in the quarterfinals either Roberto Bautista Agut or Albert Ramos-Vinolas, who eliminated the British player in the third round in Monte Carlo despite trailing 4-0 in the deciding set.
Murray was originally going to skip the Barcelona Open but decided to play after that loss to Ramos-Vinolas. He is looking to regain his form going into the French Open following a right elbow injury that kept him out of action earlier this year.
In other third-round matches, fourth-seeded Dominic Thiem of Austria defeated Daniel Evans of Britain 7-6 (5), 6-2 to set up a quarterfinal against lucky loser Yuichi Sugita of Japan, who beat seventh-seeded Pablo Carreno Busta of Spain 6-3, 6-3.
"It was my best win. It's unbelievable," said the 91st-ranked Sugita, who entered the main draw only after countryman Kei Nishikori withdrew with a right wrist injury. "This was very important for my life."
Sugita is the first lucky loser to reach an ATP quarterfinal since Lucas Pouille reached the final four last year in Rome.