Juan Martin del Potro crushes Filip Krajinovic in Miami Open pre-quarters

Filip Krajinovic returns to Juan Martin del Potro during the Miami Open. | AP

Juan Martin del Potro returns to Filip Krajinovic during the Miami Open. | AP

Filip Krajinovic reacts after missing a point against Juan Martin del Potro during the Miami Open. | AP

Juan Martin del Potro reacts after winning a point against Filip Krajinovi during the Miami Open. | AP

Filip Krajinovic hits a forehand to Juan Martin del Potro during the Miami Open. | AP

Juan Martin del Potro, right, shakes hands with Filip Krajinovic after winning their match at the Miami Open. | AP