There was another encouraging performance from Andy Murray in Antwerp as he saw the back of eighth seed Pablo Cuevas in straight sets.
Novak Djokovic and Roger Federer face tough tests next after reaching the Shanghai Masters quarter-finals.
David Goffin ran Roger Federer close but the Swiss star felt he had fortune on his side as he sealed a Shanghai Masters quarter-final spot.
David Goffin offered stern opposition to Roger Federer, but the 20-time grand slam champion battled to victory at the Shanghai Masters.
With four Shanghai Masters titles to his name, Novak Djokovic pushed on to the third round with victory over Denis Shapovalov in China.
David Goffin was unable to slow down Novak Djokovic in Tokyo, with the in-form top seed once again winning in straight sets.
World number one Novak Djokovic did not feel he could have played any better as he eased to another win over Lucas Pouille.
Marin Cilic will have to wait for a 500th tour-level win after he was knocked out of the Japan Open by an inspired Hyeon Chung.
World number one Novak Djokovic will face Lucas Pouille in the last eight in Tokyo after getting past Go Soeda.
In his first outing since losing in the final at the US Open, Daniil Medvedev brushed aside fellow Russian Evgeny Donskoy.