Tigres UANL dominated their home leg of the Copa Libertadores final but were unable to breach River Plate's stubborn defence.
River Plate frustrated Tigres UANL, holding the Liga MX club to a 0-0 draw at home in the Copa Libertadores final's first leg, but the Argentines will be without their coach and a player next week.
A first-half yellow card to Gabriel Mercado means the full-back will be suspended for the second leg in Buenos Aires on August 5, while River coach Marcelo Gallardo will watch the game from the stands after being sent off in Mexico on Wednesday.
Despite those two blows, River should be fairly pleased with their performance at the Estadio Universitario de Nuevo Leon, as they weathered the early storm from Tigres and then kept the match under control - for the most part - in the second half.
The hosts had a big chance to win the game with six minutes left but winger Jurgen Damm was unable to get around River goalkeeper Marcelo Barovero and then failed to pick out a team-mate with his cut-back in a perfect illustration of Tigres' wastefulness.
Tigres dominated the opening 20 minutes of Wednesday's game but were unable to capitalise.
River almost brought about their own undoing in the 18th minute when Leonel Vangioni deflected a cross onto the bar of his own goal, and soon after, Rafael Sobis sent a powerful header straight at Barovero.
With the temperature at 35 degrees Celsius at kick-off in San Nicolas de los Garza, a drinks break was allowed in the 25th minute and that seemed to settle River, who earned a string of free-kicks to slow Tigres' momentum.
The hosts suffered a blow four minutes before the break when defender Hugo Ayala limped off with an ankle injury and was replaced by Jose Rivas.
Moments later, Mercado received his yellow card for stamping on Andre-Pierre Gignac, which rules the 28-year-old out of next week's second leg due to an accumulation of cards.
At the interval, Gallardo brought on Gonzalo Martinez and Nicolas Bertolo, and the substitutes gave the visitors some much-needed energy.
Rivas pulled off an impressive sliding tackle to deny Bertolo in the area in the 51st minute, although the latter believed he deserved a penalty.
Gallardo was banished from the bench 22 minutes later, seemingly for yelling at the fourth official, before Juninho forced Barovero into a low save with a long-range free-kick.
Tigres controlled possession for the majority of the last 20 minutes but apart from Damm's one-on-one opportunity against Barovero - which he wasted - Ricardo Ferretti's men had few chances to score, which may cost them a maiden Copa Libertadores title.