Thomas started the match in front of his club’s home fans at the FC Zwolle Stadion, playing 73 minutes as his side secured their final berth with an 81st minute strike from Maikel Van der Werff after the two teams were locked at 1-1 at half-time.
Zwolle will face either Eredivisie leaders Ajax or 2013 cup winners AZ Alkmaar who meet in the other semi-final on Friday (NZ time).
Should Ajax win through, Zwolle could earn a place in the UEFA Europa League by qualifying for the Dutch Cup Final with Ajax in pole position for a berth in the UEFA Champions League as Eredivisie champions.
The Dutch Cup Final is on April 21 (NZ time).
Thomas made his All Whites debut against Japan in Tokyo earlier this month.
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