Juan Monaco had a day to forget as he was knocked out of the Swedish Open by underdog Alexander Zverev.
Teenager Alexander Zverev upset the form book as he sent fourth seed Juan Monaco crashing out of the Swedish Open on Wednesday.
Monaco is ranked 96 places above his German opponent, but Zverev progressed to the quarter-finals of the clay-court competition in Bastad with a 6-4 6-2 win in one hour and 20 minutes.
The 18-year-old showed his intent early with a break in game three and, although Monaco hit back, Zverev broke again in game seven before the rest of the set went with serve.
The writing was on the wall for Monaco in the second set when Zverev raced into a double-break 4-0 lead and held his nerve to serve out for love at 5-2.
Sixth seed Thomaz Bellucci avoided a similar fate, as he won his second-round encounter against Swedish qualifier Christian Lindell 6-3 6-4.
Monaco's Argentine compatriot Diego Schwartzman lost his first-round match 6-3 6-4 to Denis Istomin.
There was such success for Argentina, though, as Federico Delbonis progressed to round two after coming from behind to defeat Rogerio Dutra Silva 1-6 6-4 6-4.