Lucky loser Leonardo Mayer has sent top-seeded Spaniard Albert Ramos-Vinolas packing in the first round of the German Tennis Championships.
The Argentine dropped the first set to the world No.24 but prevailed after a third-set tiebreaker 6-7 (3-7) 6-3 7-6 (7-4) on Tuesday.
Andrey Kuznetsov knocked last year's runner-up Pablo Cuevas in another boilover.
The Russian battled back from a set down to overcome the second-seed Uruguayan 3-6 7-5 6-4 in a tick over two hours.
Third-seeded Russian Karen Khachanov marked his Hamburg debut with a 6-4 6-3 win over German qualifier Rudolf Moelleker.
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Wildcard Tommy Haas, appearing at his home town tournament for the first time since 2013, was defeated 7-5 6-2 by Argentine Nicolas Kicker.
German veteran Philipp Kohlschreiber cruised past last week's Croatian Open winner Andrey Rublev of Russia 6-3 6-1 while Argentine Federico Delbonis countryman Carlos Berlocq 6-7 (6-8) 7-5 6-3.
Fernando Verdasco's match with Jiri Vesely was suspended due to rain tied at one set each.
