Rayo Vallecano is a team that often surprises the big teams in La Liga, so their victory over Girona was actually quite understandable. On the one hand, Girona isn't exactly a remarkable team, and we saw that last season. Rayo have had a very good start to the season, and I hope they can be a top-four contender this season so Rayo Vallecano can play in the Champions League next season. As for Girona, I just hope they don't get relegated this season so they can still play in La Liga next season.
Girona is no longer the strong club they were in previous seasons, so their loss to Rayo Vallecano wasn't a surprise. Rayo Vallecano can surprise any team, as I saw them hold Real Sociedad and Real Betis, Real Madrid, and Atletico Madrid to draws last season. But playing more consistently and earning a chance to play in the Champions League is still very difficult, as some of the other strong teams in La Liga are much better. I also doubt Girona's chances next season, as the team seems to have lost its best form since last season.
Frankly, Girona has become an average team in La Liga. I wouldn't be surprised if they were relegated, because any possibility could happen. There's no sign of the former great Girona left in the Spanish league. Rayo won the match easily, and Girona didn't even show any signs of it. Girona is no longer a tough opponent; they're an easy one.