Nine-man Fluminense defeated Argentina\'s Arsenal 1-0 in the opening night of the Copa Libertadores group stage on Tuesday. A goal by Fred in the second minute gave O Flu the win in the first game in Group Four, which also features Boca Juniors and Venezuela\'s Zamora. Fred received the ball from Carlinhos and beat Arsenal keeper Cristian Campestrini with a right-foot strike and, even though Arsenal attacked a lot during the second period, they failed to score. Fluminense duo Wagner and Leandro Euzebio were sent off during the second half, as well as Arsenal midfielder Nicolas Aguirre. Fred told reporters in Rio: \"I enjoy the three points and the goal. This is an important win ahead of further matches. I also liked the attitude of the team. All the players are doing their best.\" Argentinian side Velez Sarsfield won 3-0 away to Defensor Sporting in Group Seven. Having won the title in 1994, Velez made an important step in the first game of the group, with Ruben Ramirez opening the score in the 41st minute. But it was not until the 80th minute that Velez scored again through Mauro Obolo, while Sebastian Dominguez netted a tremendous free-kick five minutes later. \"We managed the game very well. Defensor play well on their home field. They are a practical team. This is a good first step for us,\" Dominguez told Fox Sports. Also in Group Seven, Mexican giants Guadalajara and Ecuador\'s Deportivo Quito drew 1-1. Deportivo Quito led from the eighth minute when Matias Alustiza put the visitors ahead, but Omar Arellano levelled the score seconds before the final whistle.