Australian veteran Lleyton Hewitt crashed out in the first round of the Munich ATP event on Tuesday to Spanish qualifier Albert Ramos.
The 33-year-old took the first set but was broken five times in the next two as he fell 6-7 (6-8) 6-1 6-0 to the world No.117 from Barcelona.
Fifth seed Philipp Kohlschreiber – the 2007 and 2012 champion – was the day’s biggest casualty as he was beaten 7-5 2-6 6-4 by Uzbek Denis Istomin in front of his home supporters.
The 55th-ranked Istomin saved 11 of 14 break points to win in just over two hours, setting up a second-round meeting with Australian Marinko Matosevic.
Feliciano Lopez and Ivan Dodig were two other seeds to fall, Spaniard Lopez going down 6-3 6-4 to German qualifier Jan-Lennard Struff and Dodig beaten 7-6 6-4 by another qualifier, Brazilian Thomaz Bellucci.
Seventh-ranked Italian Andreas Seppi – the only seeded player to survive the first round on Tuesday – beat German lucky loser Michael Berrer 6-3 7-5 and will next face Ramos.
There were also wins for Austrian Jurgen Melzer, Ukraine’s Sergiy Stakhovsky and Slovakian qualifier Martin Klizan.
Klizan eased past Dudi Sela 6-1 6-2 to set up a second-round clash with No.3 seed Mikhail Youzhny and Melzer beat wildcard Alexander Zverev by the same score.
Ukraine’s Sergiy Stakhovsky rallied to beat German wildcard Peter Gojowczyk 3-6 6-4 6-1.