The 21-year-old won 6-2, 6-3 in 74 minutes to book his place in the last eight, where he will face second seed Lorenzo Musetti.

It was a clinical performance from Fils in the first set, converting both of his break-point opportunities while also saving one on his way to taking the lead.

The second set proved to be a similar story, with two more breaks of serve seeing Fils go 5-2 as he served for the match.

Nakashima managed to delay the inevitable with a break of his own, but Fils responded with another, clinching the win with his fourth match point.

Musetti also enjoyed a straight-sets victory, defeating Corentin Moutet 6-3 6-4 to reach the quarter-finals.

The Italian, who is the highest-ranked player left in the tournament, needed one break of serve in the first and two in the second to secure victory.

Elsewhere, Denis Shapalov reached the last eight of the Munich Open with a 7-6 (7-4) 6-2 win over Fabian Marozsan.