There were subplots aplenty heading into this rerun of last year’s final between two sides also battling for UEFA Champions League berths in the Bundesliga.
Both teams were eager to make their mark in a frenetic start to the contest, but it was the reigning champions that struck first through Olmo's excellent header from Marcel Halstenberg's sublime cross.
Freiburg were on the ropes after conceding another goal less than two minutes later through Benjamin Henrichs at the end of a slick counter-attack from the visitors. Timo Werner and Olmo linked up superbly to feed in Henrichs, who clinically fired his strike past Mark Flekken, and forced Christian Streich into a tactical recalculation.
Kiliann Sildillia was withdrawn and replaced by Vincenzo Grifo in a bid to stop the hosts from moving out of sight with only 20 minutes on the clock.
However, the boos started to ring round the Europa-Park Stadion when Dominik Szoboszlai added a third in a wonderfully-crafted move, with Olmo the provider once again.
Michael Gregoritsch came within inches of reducing the deficit with a left-footed snapshot as half-time approached, but Marco Rose's men scored a fourth through Christopher Nkunku’s emphatic finish before the break in an outstanding first-half display.
It was a case of damage limitation when Streich brought on Roland Sallai and Yannik Keitel at the start of the second half, but Leipzig smelled blood and were in the mood for more goals.
Konrad Laimer tried his luck with a speculative attempt from distance which Mark Flekken pushed away to safety.
However, the biggest cheer of the night came when Die Roten Bullen were reduced to 10 men after a VAR review determined that Josko Gvardiol had pulled down Sallai and denied a clear goalscoring opportunity.
Janis Blaswich saved the subsequent set-piece from Grifo as Freiburg looked to add some respectability to the scoreline.
Ugly scenes would follow inside the ground, with Freiburg’s players appealing to their fans to stop throwing objects from the stands as frustrations on the pitch started to boil over after an altercation between Lukas Kubler and Blaswich.
Gregoritsch did pull a goal back for the hosts with a fine header from Sallai’s cross, but Szoboszlai added a fifth from the penalty spot at the death to claim Leipzig’s place in the final in emphatic fashion, with a trip to Freiburg in the Bundesliga up next on Saturday.
Flashscore Man of the Match: Dani Olmo (RB Leipzig)
