TO HEAR DENNIS HOPPER TELL IT, HE had no idea he was drawing blood when he took a verbal jab at fellow actor Rip Torn on The Tonight Show last May 31. Hopper, 58, was on the couch touting his summer thriller, Speed. But when Jay Leno mentioned the 25th anniversary of Hopper's 1969 cult classic Easy Rider, Speed's demonic bomber soon found himself lighting a fuse under the 63-year-old Torn.

At issue was a disagreement that occurred in 1967. Torn, then a successful Broadway-based character actor, had been up for the part of Rider's alcoholic lawyer, George Hanson. But at dinner one night before filming began, Hopper, Rider's director, recalled, "[Torn] pulled a knife on me. He thought I was cutting him out of the picture, as He put it." When Leno asked if that was the best way to settle an argument with a director, Hopper said, "It was one way for me to say, 'We're not working together.' " (Jack Nicholson eventually got the role.)

The Tonight Show's audience laughed at Hopper's story. But Torn—who plays irascible producer Artie on HBO's The Larry Sanders Show—was not amused. On Aug. 23 he filed a suit against Hopper for slander, charging him with "hatred, ill will, malice, revenge and oppression." What's false about Hopper's account, according to Torn, is that it was Hopper who pulled the knife on him.

Why? Torn, now in Nova Scotia with his girlfriend Amy Wright, who is in a stage version of The Scarlet Letter, won't say. He insists, though, that he wasn't fired from Rider—that he quit over money.

For his part, Hopper claims to be baffled. "Rip Torn can't sleep at night because of this? Give me a break," says Hopper. Though he couldn't be reached for comment, Rider costar Peter Fonda reportedly remembers Torn and Hopper menacing each other that fateful night—with butter knives.

Whoever wins, the suit could wind up costing each actor as much as $500,000 in legal fees. Torn has offered to back off if Hopper agrees to make a retraction in five publications of Torn's choice. No way, says Hopper. Besides, he remembers the deal being full-page ads in three publications. "I said to my lawyer, 'I am not taking out three [expletive] pages anywhere saying I'm a liar about something I remember very vividly.' "