Franco Squillari of Argentina, seeking to repeat as champion in the only tournament he has ever won, advanced to the semifinals of the BMW Open by upsetting second-seeded Younes El Aynaoui in three sets Friday.
The seventh-seeded Argentine came from behind to win 2-6, 6-2, 7-6 (6), prevailing in a thrilling tiebreaker.
Top-seeded Thomas Enqvist of Sweden reached the semifinals although he had to appear on court twice Friday - first to complete a rain-delayed second-round match and then to play quarterfinals.
Squillari is now 8-0 in Munich, where he won his only ATP Tour title to date last year.
El Aynaoui, a Moroccan, is 13th in the ATP Champions Race, while Squillari entered the tournament as 42nd.
In the semifinals, Squillari will play Max Mirnyi of Belarus, who upset sixth-seeded Fernando Meligeni of Brazil 6-3, 6-4.
Enqvist first had to complete his second-round match against Ivan Ljubicic of Croatia, which was suspended with the Swede up 3-1 in the third set Thursday.
He was taken to a tiebreaker before completing a a 6-2, 6-7 (1), 7-6 (5) victory.
Enqvist then quickly ousted Jiri Novak 6-3, 6-4. Novak also had to play twice, after completing a 6-3, 4-6, 7-5 win over fellow Czech Slava Dosedel, who was seeded eighth.
Second Round Jiri Novak, Czech Republic, def. Slava Dosedel (8), Czech Republic, 6-3, 4-6, 7-5. Thomas Enqvist (1), Sweden, def. Ivan Ljubicic, Croatia, 6-2, 6-7 (1), 7-6 (5)
Quarterfinals Enqvist def. Novak 6-3, 6-4 Tommy Haas (3), Germany, def. Frederico Browne, Argentina, 6-3, 6-4 Franco Squillari (7), Argentina, def. Younes El Aynaoui (2), Morocco, 2-6, 6-2, 7-6 (8-6) Max Mirnyi, Belarus, def. Fernando Meligeni (6), Brazil, 6-3, 6-4