World number seven David Nalbandian stayed on course for his first Stockholm Open title by crushing Spaniard Albert Montanes 6-4, 6-1 in the quarter-finals on Friday.

The top seed from Argentina broke serve once in the opening set and three times in the second to set up a meeting with third-seeded Finn Jarkko Nieminen, who ousted Spain's Oscar Hernandez 6-1, 6-4.

Nalbandian, making his debut in the tournament, has yet to drop a set this week.

Japanese teenager Kei Nishikori received a walkover when his Croatian opponent, second seed Mario Ancic, withdrew through illness.

"It's weird. I was thinking about pulling out myself as I haven't been feeling too well," Nishikori told reporters.

The 18-year-old, who has been troubled by a cold and a sore knee, is chasing his second tournament win having triumphed at Delray Beach in February by beating American James Blake in the final.

Nishikori next meets Swede Robin Soderling, who put out fifth-seeded German Rainer Schuettler 6-2, 7-5.

Soderling, seeded four, broke in the final game to seal victory in one hour 13 minutes.

* 4-Robin Soederling (Sweden) beat 5-Rainer Schuettler (Germany [Images]) 6-2, 7-5; * Kei Nishikori (Japan [Images]) beat 2-Mario Ancic (Croatia)(Ancic retired); 1-David Nalbandian (Argentina) beat 7-Albert Montanes (Spain)
6-4, 6-1; 3-Jarkko Nieminen (Finland) beat Oscar Hernandez (Spain) 6-1, 6-4.

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