Copa Libertadores final set to be a 'clasico'

It will be the first time two Argentine sides face each other in the final, pitting the two halves of the Buenos Aires 'clasico' encounter in a mouth-watering two-legged tie.

Carlos Tevez's Boca secured their place in the final with a 2-2 draw away to Palmeiras on Wednesday to complete a 4-2 aggregate victory having won the first leg in Buenos Aires 2-0.

The night before, though, there was a highly contentious semi-final between Gremio and River in Porto Alegre.

The Uruguayan referee needed a protective police cordon after awarding a late penalty against the hosts that allowed River to overturn a 1-0 first-leg deficit to progress on away goals by winning the return 2-1.

Reigning champions Gremio have appealed the result to Conmebol, the South American football confederation, complaining they were the victims of two refereeing errors -- one leading to the game-winning penalty award, the other an alleged handball when River scored their opening goal.

The Buenos Aires rivals have faced each other in the Libertadores before, the last time in the quarter-finals in 2015 when River triumphed to lift their third trophy.

Boca, who last triumphed in 2007, have claimed the cup six times, a figure bettered only by another team from Buenos Aires, Independiente with seven.

The first leg at Boca's Bombonera stadium is on Wednesday with the return match at River's Monumental stadium scheduled for November 28.

It comes just two days before a G20 meeting in Buenos Aires in which leaders from around the world, including United States President Donald Trump, will be attending, meaning the city's security forces will already be heavily occupied.

As a result, the second leg could be either brought forward a week to November 21 or delayed until December 5.

This will be the last year the Libertadores final is played over two legs. From 2019 it will adopt the same format as its European equivalent, the Champions League, and hold a one-off final at a pre-designated venue.

The 2019 final will be played in the Chilean capital Santiago.