Kitzbuehel - Robin Haase of the Netherlands defeated sixth-seeded Andreas Seppi 6-4, 6-2 on Thursday to reach his second career semi-final at the Bet-At-Home Cup.
Haase needed eight set points to close out the opening set but converted his first match point against the Italian, who won just two service games.
"I played too defensively from the start but he helped me with some mistakes and I was more aggressive in the second set," said the 53rd-ranked Dutchman, who reached the semi-finals at the Dutch Open in 2007.
He will next play Pablo Andujar of Spain or Joao Souza of Brazil.
Earlier on Thursday, Haase rallied to beat second-seeded Feliciano Lopez of Spain 1-6, 6-4, 6-3 in a second-round match.
Haase and Lopez were even at 1-1 in the final set when rain interrupted play on Wednesday. Haase broke Lopez in the first game after resuming and closed out the win when the Spaniard double-faulted on match point.
Andujar routed fellow Spaniard Albert Ramos 6-2, 6-1, and Souza defeated Diego Junqueira of Argentina 6-2, 6-2. Junqueira replaced No. 3 Ivan Ljubicic, who pulled out of the event with a back injury.
Also advancing to the quarter-finals was Albert Montanes, who downed No 5 seed Philipp Kohlschreiber of Germany 6-4, 7-5, and Marcel Granollers, who defeated Croatian qualifier Antonio Veic 6-0, 3-6, 6-4.
Results on Thursday from the Bet-At-Home Cup on outdoor clay at the Mercedes-Benz Sportpark (seedings in parentheses):
Robin Haase, Netherlands, def. Feliciano Lopez (2), Spain, 1-6, 6-4, 6-3.
Marcel Granollers (7), Spain, def. Antonio Veic, Croatia, 6-0, 3-6, 6-4.
Albert Montanes, Spain, def. Philipp Kohlschreiber (5), Germany, 6-4, 7-5.
Pablo Andujar (8), Spain, def. Albert Ramos, Spain, 6-2, 6-1.
Joao Souza, Brazil, def. Diego Junqueira, Argentina, 6-2, 6-2.
Robin Haase, Netherlands, def. Andreas Seppi (6), Italy, 6-4, 6-2.
Albert Montanes, Spain, def. Santiago Giraldo, Colombia, 6-1, 7-6 (0).
Joao Souza, Brazil, def. Pablo Andujar (8), Spain, 6-3, 6-4.