It could have been a more commanding victory for the Argentine if he had been more clinical, however he still enjoyed a smooth passage into the last sixteen.
Del Potro remains in excellent form and he appears to be on a championship match collision course with Roger Federer – and he will rarely have a better opportunity to end his wait for a first Masters crown.
It’s been a tournament of shocks and surprises, but it never appeared likely that the No.6 seed would succumb to his combative opponent’s advances.
The Argentine squandered a glut of break-point chances in the opener, 10 in total, before his pressure finally told in the seventh game.
Ferrer, who has lost his baseline consistency in recent seasons, clattered a forehand long to slip 4-3 behind. Del Potro’s patience had been tested, but his perseverance finally paid off.
The Argentine had five opportunities to break Ferrer’s serve for a second time, but his gutsy rival denied him. It was a mere inconvenience for the former US Open winner, though, as a game later he pocketed the set.
The second set was a much tighter affair. Both competitors were proficient behind their respective deliveries and break-points chances were at a premium.
Ferrer did create a rare break-point opportunity in the eighth game, however del Potro averted danger with a trademark forehand winner. The set was decided by a tiebreak, and the Argentine’s superior firepower helped him avoid a decider.
Del Potro, the highest ranked seed remaining in his half of the draw, will encounter Leonardo Mayer on Thursday. The 30-year-old took out Novak Djokovic’s conqueror, Taro Daniel, for the concession of just five games.
Earlier in the day, Marin Cilic became the biggest casualty of the tournament so far. Phillip Kohlschreiber had a perfect break-point conversion rate as he overcame the Croatian 6-4 6-4.
Elsewhere on the grounds, Milos Raonic registered consecutive victories for the first time this season after a 7-5 4-6 6-2 success over Joao Sousa – and Pierre-Hugues Herbert was leading Gael Monfils 6-2 3-1 before his compatriot retired with a back problem.