Andrey Rublev has claimed some big scalps in 2019, but came unstuck against US Open runner up Daniil Medvedev in St Petersburg on Friday.
Only one Pan Pacific Open quarter-final was completed on Friday due to the rain in Osaka.
In his first outing since losing in the final at the US Open, Daniil Medvedev brushed aside fellow Russian Evgeny Donskoy.
Richard Gasquet lost for just the second time in nine career meetings with Benoit Paire in an-all French clash in Metz.
Marie Bouzkova claimed another notable scalp in 2019 as Elina Svitolina retired at the Guangzhou Open.
An expectant crowd were given an early scare before Naomi Osaka pulled through in straight sets at the Pan Pacific Open.
After dropping down to the Challenger Tour for the second time this season, Jo-Wilfried Tsonga hit the ground running in Metz.