Rafael Nadal advanced to the quarterfinals of the Madrid Open on Thursday, though it wasn’t as easy as many may have expected. The King of Clay defeated a persistent Sam Querrey as he continues his run towards a third straight championship in 2016.

The No. 2 seed Nadal struggled in the early going, falling behind 3-0 and 4-1 in the first set. But he rallied to win the set, and finishing off the American in a total of 70 minutes, 6-4 6-2. 

"It was a tough start," Nadal said. "He was hitting every ball hard and was being successful. I couldn't get to the ball. It took me a while to get into a rhythm."

Nadal struck 10 winners against 12 unforced errors. The Spaniard won 71 percent of his first-serve points.

Thursday’s results set up a quarterfinals matchup on Friday between Nadal and Joao Sousa, who defeated Jack Sock. That match will start no earlier than 10 a.m. ET (4 p.m. local time). The winner will go on to a semifinals match against either Tomas Berdych or Andy Murray.