Isco was back in action after almost four months sidelined due to a leg fracture.
"After so long, to play again, on my (34th) birthday no less, and with a win... I'm really happy," he told Movistar immediately after the match.
"The truth is, we were coming off a really bad run of form, which these days, if you want to aspire to major goals, is unacceptable, and it's a shame.
"Losing is part of football, but the way we let qualification slip away on Thursday (in the Europa League) is something that really hurts, something we can't allow playing at home, and we're very disappointed, especially because of the missed opportunity.
"We had high hopes for that competition, and well, now that it's over, we have to look ahead. The three points today were very important, and we have six finals left that we have to fight for as hard as we can.
Victory over Girona consolidates Betis' position as sitting fifth on the LaLiga table.