Soccer-River on course after Tigres tread water at home

* River coach Gallardo dismissed for shouting at official * Tigres dominant but unable to break deadlock (Fixes typo in first par) MONTERREY, Mexico, July 29 (Reuters) - River Plate moved into position to claim a third Libertadores Cup title on Wednesday when the Argentine side held Tigres to a 0-0 draw in the first leg of the final, giving them the edge going into the home fixture in Buenos Aires next week. Tigres pushed forward for a majority of the contest but failed to score at home for the first time in this year's competition and were left kicking themselves for not building up any kind of lead to take to the southern hemisphere. "We created opportunities but unfortunately we couldn't put them away," Tigres midfielder Egidio Arevalo Rios said in a pitchside interview. "We can win in Argentina, we have to be attentive and pressure them from the off." Although the more experienced Argentine side contained their hosts in midfield, Tigres had the best chances of a pulsating contest. River's Leonel Vangioni deflected a cross onto his own crossbar after 17 minutes and Rafael Sobis could only direct a header straight at visiting goalkeeper Marcelo Barovero from six yards out. The home side could have grabbed a vital advantage with seven minutes remaining when Jurgen Damm rounded Barovero but he was forced too wide and could not create an angle to shoot. "It was hard, they didn't come to play, they came to defend," Sobis said. "But I think we deserved to win, we pressured them and we created chances, but we didn't score. "There it will be another game, they'll have to come at us so maybe we can take advantage. They will have their fans behind them but often it is better to play away from home." A sell-out crowd is expected at the Monumental stadium in the hope of seeing River win the competition for the first time since 1996. However, River are likely to have coach Marcelo Gallardo watching from the stands after he was sent off in the 72nd minute for yelling at the fourth official. Gallardo is aiming to become just the seventh man to win the Libertadores as both a player and a coach. "Not losing was a good result for us given the difficulties we had today," Gallardo said. "The return leg will be a totally different game. We can't let this cup get away from us at home." A win for Tigres would make them the first Mexican side ever to win a competition considered the South American equivalent of the Champions League. (Writing by Andrew Downie; Editing by John O'Brien/Greg Stutchbury)