Pablo Carreno Busta saw his title defence at the Hamburg European Open come to an early end as he crashed out on Wednesday, while Andrey Rublev progressed with ease.
Carreno Busta fell to a 6-3 1-6 7-6 (7-5) second-round defeat against Slovakian Alex Molcan, who progressed to a fourth ATP Tour quarter-final this season.
World number 48 Molcan will next meet Borna Coric after the Croatian eased past Tallon Griekspoor 6-3 6-4, registering back-to-back tour-levels wins for the first time in 17 months.
Second seed Rublev coasted through his first-round clash with Ricardas Berankis, triumphing 6-3 6-4 as he improved his record at the ATP 500 clay-court event in Germany to 10-2.
"I am happy with my performance. Ricardas is a really tough player," said world number eight Rublev, who is aiming for his fourth title of the season after success in Marseille, Dubai and Belgrade.
"He hits the ball really hard and plays fast, so I had to bring intensity from the first game. I am really happy with how I was serving today and I hit some great shots from the baseline.
"The game he broke me in the second set he played really well. He returned really aggressively and I don’t think I made one first serve. But then I kept [my] focus and broke him straight away again."
Alejandro Davidovich Fokina was another comfortable winner, easing past Jozef Kovalik 6-2 6-2 to set up a quarter-final contest with Lorenzo Musetti, who beat Emil Ruusuvuori 6-4 7-5.
Play was suspended early at the Swiss Open due to bad weather, with Spaniard Jaume Munar downing Alexander Ritschard 6-3 6-3 in the only match of the day to reach the last eight.
That meant top seed Casper Ruud will have to wait until Thursday to face Jiri Lehecka in Gstaad, with third favourite Roberto Bautista Agut also seeing his match with Juan Pablo Varillas pushed back a day.