In reply to Richard Carter:
Ed Harris vs. Michael Biehn in The Abyss
Ernest Borgnine vs. Lee Marvin in Emperor of the North
Charles Bronson vs. various opponents in Hard Times (aka The Street Fighter)
Michael Pare vs. Willem Dafoe in Streets of Fire
Uma Thurman vs. Daryl Hannah in Kill Bill Vol. 2
Harrison Ford vs. Daryl Hannah in BladeRunner
Jet Li's fights in Fearless
Timothy Treadwell vs. a mean old bear in Grizzly Man