Johann Berg Gudmundsson scored the only goal as AZ Alkmaar picked up an impressive win at Maccabi Haifa in their Europa League Group L clash.
The Iceland international struck with 20 minutes to go and on a quiet evening at the Kiryat Eliezer, it proved decisive.
Maccabi did have their chances on the night - Rayo was excellent and drove them forward - but they were largely toothless in the final third.
Nemanja Gudelji recorded the first effort of the night - a loosener that Bojan Saranov dealt with, before Rayo responded for Maccabi.
There appeared to be little between the sides but it took a brilliant stop from AZ keeper Esteban Alvardo to keep the scores level as he tipped over Hen Ezra's goalbound 21st-minute effort.
Alvardo was involved again just after the half-hour as he flicked Rayo's shot away, and the former Barcelona man went close again as the break approached with a shot which whistled wide.
Off-target shots remained the order of the day in the second half as Rayo and Aron Johannson traded efforts, and when Rayo hit over again, the game was in danger of repeating itself en masse.
A good did eventually arrive, though, with AZ making the decisive breakthrough with 70 minutes on the clock.
Nick Viergever created it, swinging in a left-wing cross which fell for Gudmundsson tucked away.
Gustavo Boccoli then hit the bar for Maccabi with a free-kick, but no pressure followed and AZ eased home.