German Molleker, ranked 179th, had been the better player in the first set but a brief stoppage ahead of the second set changed the momentum of the contest.

Draper began to assert his powerful game after the resumption and lost only two more games, pulling away to claim a 4-6 6-1 6-1 victory.

In the last eight Draper, who is ranked 46th, will take on either third seed Taylor Fritz or Spanish qualifier Alejandro Moro Canas.

Speaking in an on-court interview, Draper said: “I think Rudy played an amazing level in the first set. The conditions were very rainy and very slow. In the second and third, the sun comes out and I start feeling better. I’m really proud of the way I played.”