The Icelandic forward struck in the 67th minute, finishing after a pass from Ander Barrenetxea to settle a closely contested game and give Pellegrino Matarazzo’s side three points after a demanding run of fixtures.
San José, returning to the stadium where he had previously worked, felt Rayo had deserved at least a draw.
“We are very frustrated. There is a lot of pain because we did not deserve to lose,” he said. “The first half was even. They did not cause us much damage. They had a few dangerous attacks, but we also had some very good ones. We could have got more from the game.
“In the second half, just when we were playing our best, that fatal goal came from one of our own corners. It hurts to leave with nothing. Today the goal was denied to us. We deserved at least a draw.”
The Rayo Vallecano coach was particularly disappointed with his side’s finishing, despite believing their attacking work had created opportunities.
“We practise our attacking play a lot and we have players with ability. The final finish is something we work on continually, and we also have to keep working on the pass before it.”
San José also explained that Jozhua Vertrouwd’s early withdrawal was forced by a physical problem.
“He asked to come off because of a physical problem. I do not know the details yet; the doctor will tell me. He was left stuck after a fairly strong action, so we had to make the change.”
For Matarazzo, the victory was especially satisfying given the quality of the opposition and the workload his players had faced.
“It was not an easy match,” he said. “I think we started very well and had a good first half, in which we created plenty of chances and opportunities to take the lead. Orri and Ander had the two best chances early on, and we also had dangerous situations across the area with a very clear shot that we did not turn into the 1-0.
“The second half was very even and open. Rayo had their opportunity, but then we scored and won. Suffering is also part of football.”
Matarazzo was pleased with his team’s defensive organisation, although he placed greater importance on collecting the points than keeping a clean sheet.
“I am happier about the three points. Sometimes it is not easy to create chances. When the attacking game does not flow as much, you need to defend well and concede very few opportunities. I think we did that today.
“We defended as a team, just as we did against Lyon. I am very happy with the defensive performances in the last two matches.”
The Real Sociedad coach also revealed his concern over Barrenetxea, who was forced off with a suspected muscular injury.
“Everything indicates a muscular injury, although we do not yet know how serious it is. We have to wait for medical tests. It is very unfortunate because Barrene was in excellent form and was having a great match. He is very important to us, but he will come back stronger.”