An injury time goal by Real Betis striker Borja Iglesias gave his side a 1-1 tie against Rayo Vallecano in their Copa del Rey semifinal second leg, securing Betis a 3-2 aggregate win and a place in the final of the Copa del Rey against Valencia.Betis went into the game as clear favourites to qualify for the final after their 2-1 win at the Vallecas in the first leg, coupled with the fact that Rayo have the worst away record in La Liga, but the first half certainly didn't confirm those expectations as both sides swapped attacks in an open game.Despite the open game and the fast, high-energy football, goalscoring chances were in short supply, with Luca Zidane's save to frustrate Juanmi's header the only shot on target, although the Rayo keeper had to be attentive after Alex Moreno's deflected cross after the Betis left-back had raced into the Rayo area, Xinhua reports.The second half began with Rayo's Sergi Guardiola setting up Pape Ciss to volley over at one end, before at the other end the impressive William Carvalho saw Ciss deflect his 25-meter shot just wide.As the second half progressed, Rayo began to tire and their need for a goal saw them commit more players forward and Betis began to find spaces on the break.Just as it looked as if the game was Betis' for the taking, Rayo substitute Bebe levelled the aggregate score with a spectacular 30-metre free kick, before Iglesias scored the decisive goal for Betis to send the home fans into ecstasy.