MUNICH (AP) -- Veteran Tommy Haas' last appearance at the BMW Open ended in a 6-4, 7-5 defeat to fellow German Jan-Lennard Struff in the second round on Wednesday.
Struff hit seven aces and saved five of the seven break points he faced to win in just under an hour and a half against the 39-year-old Haas, who won the clay-court tournament in 2013.
Struff goes on to a quarterfinal against No. 3 Alexander Zverev, last year's runner-up. The 20-year-old Zverev hit five aces to beat Jeremy Chardy of France 6-4, 6-4.
Earlier, German qualifier Yannick Hanfmann upset eighth-seeded Thomaz Bellucci of Brazil 7-6 (5), 4-6, 7-5 to reach the quarterfinals.
The 273rd-ranked Hanfmann converted seven of his 16 break opportunities to win in 2 hours, 19 minutes and line up a match against second-seeded Roberto Bautista Agut of Spain.
Bautista Agut was also made to work hard, rallying to beat Marius Copil of Romania 4-6, 7-6 (3), 7-5 in just under 2 ½ hours.