MEXICO CITY, Sept 21 (Reuters) - UNAM ended a six-match winless run when they beat Bolivia's The Strongest 3-1 in a Copa Sudamericana tie played Tuesday.Argentina forward Bruno Marioni and Antonio de Nigris gave the Pumas a 2-0 halftime lead in the second round, first leg tie, as Hugo Sanchez's team put their dismal domestic form behind them. Although Paraguayan Pablo Escobar pulled one back in the 83rd minute, former River Plate striker Martin Cardetti restored the two-goal advantage in injury-time. In a bad-tempered second half, The Strongest had veteran midfielder Luis Cristaldo sent off in the 52nd minute for a foul on Leandro Augusto and the Pumas had Gonzalo Pineda dismissed in the 88th for retaliation. The win was a relief for the Pumas, who have gone through one of their worst spells since former Real Madrid and Mexico striker Sanchez took over as coach four years ago. Sanchez, who has seen his own hopes of coaching the Mexican national side collapse, said at the weekend that his team were not good enough to reach the knockout stages of the Mexican Apertura championship. UNAM's recent results have included a 3-1 home defeat by Pachuca and a 5-0 drubbing by arch-rivals Cruz Azul.