Controversial clash in the penultimate race of the 1994 DTM.
Alfa Romeo's Alessandro Nannini is the only driver left in the race who can mathematically catch championship leader, Mercedes' Klaus Ludwig. He is set to take the long but mathematically possible title fight to the final round when Mercedes' Roland Asch, who was one lap down, deliberately hits Nannini going into the hairpin, forcing him down the order. This hands the title to Asch's fellow Mercedes driver Klaus Ludwig.
Nannini pits and comes out just behind Asch. As revenge for costing him a chance at the title, Nannini very deliberately runs into the back of Asch.
The commentator in the above video (2:27) says "Asch will be appalled by this, a thousand apologies [to Nannini] because he's not the sort to pull this kind of number" but Asch would later sour his reputation again in the finale of the 1999 STW in the very last race on the very last lap in the very last corner.
Without overcomplicating the situation, as it stands Christian Abt will just pip Uwe Alzen to the title with Alzen and Abt in 2nd and 3rd place on the final lap. Uwe Alzen in the Opel Vectra collides with Abt's Audi teammate Kris Nissen at the chicane, who was a lap down and clearly holding Alzen up. Roland Asch, in an Opel like Alzen, also avoids the collision and rams Abt at the very last corner, taking them both out of the race. Alzen's car limps to the line with severe suspension damage but makes the finish, thus taking the title from Abt at the very last corner in extremely controversial circumstances.
Alzen is even declared the champion as such but months later, on appeal, the DMSB (German Motorsport Federation) took the extraordinary decision to declare the final race on the penultimate lap prior to these incidents and awarded the title to Christian Abt. This appeal was all the more extraordinary because as you can see, there was little TV footage to analyse Asch's manoeuver; amateur footage recorded by a fan was used to conclusively prove Asch's malice.
The kicker? Asch had already been black flagged for an incident in this race.