Australia midfielder Brett Holman scored one and created the other Thursday as AZ Alkmaar beat Velencia 2-1 in the quarterfinals of the Europa league on Thursday.
Holman put AZ in front with a powerful volley in the 45th but Mehmet Topal levelled for Valencia six minutes later off a header.
Maarten Martens converted Holman's cross from six yards in the 78th to earn the win for AZ.
Roberto Soldado had two chances to win the match for Valencia just before Mertens'winner but was twice denied by AZ goalkeeper Esteban Alvarado Brown.
The second leg is set for next week.