Girona lost 1-0 at Getafe on Saturday, with a first-half goal from teenager Jesus Santiago, leaving their hold on second place in the LaLiga standings in jeopardy.
The Catalans slipped further back in the title race and stand on 62 points, 10 behind leaders Real Madrid and one clear of third-placed Barcelona, who visit Atletico Madrid on Sunday.
"I have no words to describe this defeat. We came here for the three points that were very important and we couldn't get them," Girona forward Savio said.
"We knew it was going to be very difficult. We worked hard this week but it wasn't enough. Now it's time to carry on and raise our heads."
The hosts grabbed the lead in the 33rd minute through a fine passing move, with Ilaix Moriba finding Santiago unmarked inside the box for an easy finish and his first goal in the Spanish top flight.
"I still can't believe it. I'm very happy for the goal and for the three points," the 19-year-old Santiago said.
"There is a lot of work behind it. I'm very happy to help the team. We knew Girona were a very good team. We knew we had to score the one chance we had."
The visitors came close to equalising late on but Getafe keeper David Soria denied Artem Dovbyk and Cristhian Stuani headed wide as Girona fell to their fourth successive away defeat.
The win moves Getafe to ninth in the standings with 38 points, eight points off the European spots.