But the British star - who, ironically, only made it into the main draw in Zagreb as a lucky loser - fought back in style to claim a 1-6 6-1 7-6(4) victory, earning a quarter-final against either third seed Philipp Kohlschreiber.
Evans was overlooked for Britain's successful Davis Cup tie against the USA in San Diego last week, but looks set to give team captain Leon Smith a real selection headache if he continues with his form.
The 23-year-old made the third round of the US Open and the last 16 at Queen's last year, but has never been as far as the quarter-finals of an ATP Tour event.
The victory comes on the back of a remarkable change in fortunes for British tennis, with Murray and James Ward spearheading the Davis Cup victory in the USA, while Heather Watson and Johanna Konta got their Fed Cup campaign off to a winning start against Latvia on Wednesday.
ATP Zagreb - round 2
Results from the Zagreb Indoors Men's Singles on Thursday
1-Tommy Haas (Germany) beat Benjamin Becker (Germany) 4-6 6-3 6-3
4-Ivan Dodig (Croatia) beat Ivo Karlovic (Croatia) 7-6(5) 6-3
Andrey Kuznetsov (Russia) beat 8-Igor Sijsling (Netherlands) 1-6 6-3 7-6(5)
3-Philipp Kohlschreiber (Germany) beat Andrey Golubev (Kazakhstan) 6-4 6-2
Bjoern Phau (Germany) beat 2-Mikhail Youzhny (Russia) 4-6 7-5 6-1
Daniel Evans (Britain) beat Michael Berrer (Germany) 1-6 6-1 7-6(4)
Dudi Sela (Israel) beat Lukas Lacko (Slovakia) 6-3 6-2
ATP Montpellier - round 2
1-Richard Gasquet (France) beat Paul-Henri Mathieu (France) 6-1 6-3
7-Edouard Roger-Vasselin (France) beat Dustin Brown (Germany) 6-3 6-4
Albano Olivetti (France) beat Nikolay Davydenko (Russia) 7-6(5) 6-7(5) 7-5
5-Gael Monfils (France) beat Joao Sousa (Portugal) 6-3 6-2
Marc Gicquel (France) beat 2-Gilles Simon (France) 7-6(4) 6-3
6-Jarkko Nieminen (Finland) beat Pierre-Hugues Herbert (France) 7-6(5) 7-6(5)
Denis Istomin (Uzbekistan) beat 4-Dmitry Tursunov (Russia) 7-5 6-4
Vina del Mar International - round 2
5-Jeremy Chardy (France) beat Pablo Carreno (Spain) 6-3 7-6(5)
Daniel Gimeno-Traver (Spain) beat Horacio Zeballos (Argentina) 6-2 6-4
Taro Daniel (Japan) beat 8-Federico Delbonis (Argentina) 1-6 7-6(5) 7-6(7)
3-Nicolas Almagro (Spain) beat Martin Alund (Argentina) 4-6 6-3 6-4