Roberto Bautista Agut maintained his 100 per cent record against Andreas Seppi as he cruised into the semi-finals of the Zhuhai Open on Friday.

The Spaniard made it four straight wins against Seppi, with the 6-2 6-2 result not just securing a place in the last four of the tournament but also strengthening his bid to qualify for the season-ending ATP Finals.

"My game is getting better and that's why I'm climbing in the ATP Rankings," the world number 10 told the ATP Tour website after triumphing in one hour and 19 minutes.

Bautista Agut is joined in the semis by compatriot Albert Ramos-Vinolas, who knocked out third seed Gael Monfils 7-5 6-4 to set up a clash with Adrian Mannarino - a 6-1 6-4 winner over Damir Dzumhur.

Meanwhile, Alex de Minaur came through via a deciding set for a second successive outing. Having battled back to knock out Andy Murray in the previous round, the seventh-seeded Australian triumphed 6-2 4-6 6-4 against fourth seed Borna Coric. His reward is a showdown with Bautista Agut on Saturday.

At the Chengdu Open, Alexander Bublik battled back from the brink of defeat to upset Grigor Dimitrov, denying the fourth seed a 300th career win.

Bublik - who served 35 aces - saved two match points in the tie-break to decide the second set before eventually going on to triumph 5-7 7-6 (9-7) 7-6 (7-3). 

Next up will be South African lucky loser Lloyd Harris, who made it through to a maiden semi-final on the ATP Tour courtesy of a three-set victory over Joao Sousa.

The other side of the draw will see eighth seed Denis Shapovalov take on Pablo Carreno Busta, the pair recording respective triumphs over Egor Gerasimov and Cristian Garin in their quarter-final ties.