Top-seeded Daniil Medvedev's 12 aces weren't enough as the Australian Open runner-up lost 7-6 (4), 6-4 to Dusan Lajovic in the first round of the ABN AMRO World Tennis Tournament on Wednesday.
It wasn't the day's only upset in Rotterdam, with third-seeded Alexander Zverev also losing.
Medvedev had 25 unforced errors against Lajovic's 12, along with eight double-faults, and he broke his racket in frustration. It was the the third-ranked Russian first match since his straight-set loss to Novak Djokovic in the Australian Open final.
“I think I was very focused the whole match," Lajovic said. “This was the key today, not to make the little mistakes.”
The 30-year-old Serbian player faces Borna Coric of Croatia in the second round.
Alexander Bublik beat Zverev 7-5, 6-3 to set up a second-round meeting with Tommy Paul. Zverev, coming off a quarterfinal loss to Djokovic in Australia, went a break up in each set against Bublik but each time was then broken twice himself.
Three-time Grand Slam champion Andy Murray’s tournament run ended in a second-round loss to fourth-seeded Andrey Rublev, who won 7-5, 6-2. Murray hasn't got past the second round of an ATP event since reaching the third-round in Cincinnati in August.
No seeded players remain in the top half of the Rotterdam draw after Alejandro Davidovich Fokina knocked out fifth-seeded Roberto Bautista Agut 6-2, 7-6 (3) in an all-Spanish match. Medvedev, Zverev and Felix Auger-Aliassime were all in that half of the draw but none reached the second round.
Sixth-seeded David Goffin needed just over an hour to beat Jan-Lennard Struff 6-4, 6-0. He'll meet qualifier Jeremy Chardy in the second round.