Despite Cristián Muñoz's joining the team, after the Cejas' departure of the club, Wirth played in Colo-Colo's opening game of the Clausura Tournament, and his club won 4–1. On 2 August 2007, Wirth was chosen ahead of Muñoz to start in the Copa Sudamericana first stage game against Real Potosí. He produced a man-of-the-match performance, saving numerous challenging shots which helped Colo-Colo to draw the game 1–1. Wirth continued his run of starts in his next six appearances, contesting the post with the goalkeeper Muñoz, that finally was selected as the first-choice goalkeeper, due to his good performances in the field, after conceding only one goal in the playoffs, that meant Wirth was the second-choice goalkeeper of Colo-Colo.