John Isner won his first round match against Filip Krajinovic of Serbia in straight sets 7-6 (8) 6-4 in one hour and 37 minutes.
The American served 29 aces and hit 41 winners in the win while the Serb hit 12 unforced errors in the loss.
The first set stayed on serve until 3-3 when the world number 49 had a chance to break and earned the first break of the match but was broken right back the following game as Isner came up with a stunning backhand return winner to go back on serve.
The opener went into a tiebreak which was extremely tight and at 4-3 it was Krajinovic with the first break as the American served an untimely double fault.
Isner won the next two points to level the breaker at 5-5 and the following point the Serb had a set point on the American’s serve but was denied by one of Isner’s 29 aces in the match.
At 9-8 the world number 25 came up with a sublime forehand winner to break and win the first set.
Isner carried the momentum into the second set and broke serve to take an early 1-0 lead with a stunning passing shot.
The set stayed on serve until 4-3 when the Serb had a chance to break back but again the American was able to save it and cruised from there for his first win in the Spanish capital.
Isner will next face the winner of the first round match between Cameroon Norrie and Soonwoo Kwon in the second round. His head-to-head record against the Brit is 2-2 with their last meeting being this year in Acapulco. The American has is yet to play Kwon on the Tour.
