Boca Juniors hold the advantage going into the second leg of their Copa Libertadores quarter-final tie after playing out a 1-1 draw against Nacional on Thursday.
Boca struck first through Frank Fabra in a game largely dominated by Nacional, but the hosts were able to hit back through Sebastian Fernandez towards the end of the second half.
The away goal sets up Boca nicely for the return leg at La Bombonera in Buenos Aires, but three-time champions Nacional are undefeated away from home in 2016.
The Uruguayan outfit were buoyed by the noisy home support at Gran Parque Central and signalled their attacking intent early, playing in several dangerous crosses into the box.
It would be the theme of the night, with Nacional attacking and Boca happy to sit back and threaten on the counter attack.
After a scoreless first period Nacional began to throw more men forward in the latter stages of the second half, becoming vulnerable on the counter.
And Boca managed to capitalise on some space at the back and a slip from a Nacional defender to take the lead through Fabra in the 70th minute.
But Nacional refused to sit back and ensure they did not concede another away goal, with Fernandez striking the equaliser just six minutes later.
Nacional could not find a winner in Montevideo, settling for a 1-1 draw, meaning they have to at least score once in the second leg to have a chance of going through to the semi-finals.
Meanwhile, a wonder strike from Walter Montoya ensured Rosario Central go into their return leg with Atletico Nacional holding a 1-0 advantage.
Montoya opened the scoring just six minutes into the contest at Estadio Gigante de Arroyito in Santa Fe with a long-range effort following an Atletico turnover in defence.
The Argentinean side had the upper hand for the majority of the contest and would have felt unlucky not to build a bigger advantage before next week's second leg in Medellin, Colombia.
The 1-0 win for Rosario also condemned Atletico to their first loss of the campaign, meaning Boca are the only side remaining still unbeaten in 2016.