The Copa Libertadores will witness its first ever Superclásico final, after Boca Juniors secured a 2-2 draw against Palmeiras in São Paulo to secure a 4-2 aggregate victory.
The result means that the Xeneize will now meet their arch-rivals, River Plate, in a two-legged showdown in the region's most important club competition – with both matches set to take place in Buenos Aires in November.
River had secured their place on Tuesday night, after turning round their tie against Brazilian defending champions Grêmio to win 2-1 on the night and qualify on away goals.
Super-sub striker Dario Benedetto scored Boca's second goal last night on 70 minutes, all but ending the tie. Fellow forward Ramón 'Wanchope' Ábila, who he replaced when coming onto the pitch, had scored the first after just 18 minutes, putting the Brazilian side on the ropes.
Benedetto's proved to be the difference in both matches, having turned around the first leg in Buenos Aires after coming on as a replacement and bagging two goals.
Palmeiras, who had chances throughout the match, couldn't find the back of the net until the 52nd minute, when captain Luan broke their duck in the tie. They went in front on the night when Gustavo Gomes scored from the penalty spot in the 60th minute but the away goals Boca had scored had left them up against it.
Boca, who have won the Libertadores title seven times, is seeking its first crown since 2007. River, meanwhile, have won the tournament three times, though it won the title as recently as 2015.
The outcome sets up a policing headache for the government, with the second leg of the final set to be played on March 28 at River's Monumental stadium. However, that would be just two days before the G20 leaders summit in Buenos Aires begins, with Argentina's holding the group's presidency.
City government officials said earlier today to the Noticias Argentinas news agency that the clubs would not be granted permission to go ahead with the match on that day, despite the wishes of CONMEBOL, the region's higest football authority and organisers of the tournament.
Given that, it is likely that the second leg would be played on Wednesday, November 21, one week earlier than originally scheduled, with the first leg taking place at Boca's La Bombonera stadium on November 7, as originally planned.
Those dates are yet to be confirmed, though one thing is certain. Fans of either club face a sleepless few weeks ahead of them, with many likely to be distressed by dreams of glory and nightmares of failure.
For one President Mauricio Macri, formerly Boca's president in the mid-90s to 2000s, has already expressed his fears over a Superclásico showdown for the Libertadores crown.
“I think it would be better for one of the finalists to be Brazilian. Whoever. That way we will not have that final which will have us Boca and River fans in bed for three weeks. Do you know what it is like to go three weeks without sleeping. It is crazy, eh, too much.”
River, however, may face further complicates ahead of the two-legged final against their arch-rivals.
CONMEBOL confirmed tonight that it will investigate River Plate coach Marcelo Gallardo for allegedly speaking to his players during half-time, despite being suspended from the dressing room and the touchline.
The body's president, Alejandro Domínguez, confirmed Wednesday that the body's disciplinary tribunal will look into a complaint filed by Grêmio. The Brazilians were beaten at home by a 2-1 River victory in the second leg of the Copa Libertadores semi-final.
"Any complaint should be introduced to the disciplinary unit within time and form contemplated by regulations, and it will be of exclusive competence of the disciplinary tribunal," Domínguez said on Twitter.
Gallardo acknowledged talking to his players at the break when his team was losing 1-0 to the defending champions. River had lost by the same score at home last week.
"I took that audacity because I thought the players needed it and I needed it too," Gallardo said on Tuesday in Porto Alegre. "I broke a rule, I recognise and take responsibility, but it is what I needed and I don't regret it."
Gallardo was suspended for the match after being found guilty of delaying his team's return to the pitch in several Copa Libertadores matches.
Grêmio requested CONMEBOL to annul River's victory and let them progress to the final instead. The club issued a statement saying the Argentine side had violated the spirt of fair play and accused Gallardo of also communicating with his assistants by walkie-talkie, a claim that the coach denies.
After River is officially informed of Grêmio's request it will issue its defence before a CONMEBOL disciplinary tribunal.