World Cup winner Rocio Galvez's first-half strike gave Real Madrid a 2-1 lead in their women's Champions League final qualifying round tie with Norwegians Valarenga on Wednesday.
Real Madrid, who were knocked out in the group stage last year, took an early lead through Claudia Zornoza.
Felicia Rogic levelled for Valarenga before the half-hour mark but Zornoza's Spain teammate Galvez struck in the 44th minute.
Real Madrid could not find another goal, though, and take only a slender advantage into next Wednesday's second leg.
Elsewhere, Roma, quarter-finalists last season, eased to a 3-0 victory over Ukrainians Vorskla Poltava.
Ajax also put one foot firmly in the group stage with a 6-0 first-leg thumping of Zurich in Switzerland.
