Diego Schwartzman got a morale-boosting victory at the German Tennis Championships on a mixed day for the big names in Hamburg.
Second seed Schwartzman had one won one of his previous five matches on the ATP Tour, but he was able to battle past Casper Ruud 6-4 2-6 6-2 on Monday.
The Argentinian required just over two hours to get through, but other notable stars were not quite so fortunate.
David Ferrer's miserable year continued as he lost to teenager Rudolf Molleker, registering just his second ATP World Tour-level win.
Fourth seed Damir Dzumhur went out to qualifier Jozef Kovalik, while Pablo Carreno Busta required a third-set tiebreak to see off German veteran Florian Mayer.
Elsewhere, highly rated 17-year-old Feliz Auger-Aliassime progressed at the Swiss Open Gstaad with a straight-sets win over Guido Andreozzi.
Yannick Hanfmann, a finalist last year, could not join the teenager in the second round, however. He lost 3-6 6-3 7-6 (7-4) to Jurgen Zopp.
