Massachussets: Chile star Arturo Vidal was ecstatic after an incredible victory over Mexico that took them to the semi-finals of the Copa America football tournament, but the midfielder remained wary of another meeting with Argentina skipper Lionel Messi, whom he named as the best player in the world. An incredible four-goal haul from Eduardo Vargas set the defending champions on the way to a crushing 7-0 victory on Saturday, setting up a last-four clash with Colombia. If they manage to overcome Columbia, Argentina or the United States will then await them in the final, and Vidal knows that Messi can make the difference. "Everybody knows what Messi is: he is the best player in the world," the Bayern Munich star was quoted as saying by goal.com after their win against Mexico. "I said that because in that game a 2-1 defeat for Chile Argentina came out with intensity and started to pressure us, unlike in other games. But with Messi on the pitch everything changes." A yellow card for Vidal against Mexico will keep him out of the semis, and he admits that missing such a big game is a significant blow. "I am sad, but confident in what my team-mates can do. These cames come with a risk, I hope I can play the final," he said. "I knew I could pick up another yellow right from the first game against Argentina. It would be great to meet the Argentines again because they are the best national team in the world and we are up there fighting,” the former Juventus midfielder said.