The Alfred Hitchcock Hour (1962)

S3E5 See the Monkey Dance

On his way to visit his girlfriend, George encounters a mysterious stranger who limps and instills a deep sense of fear in him. It turns out the man is her envious husband, and the meeting was orchestrated by George's girlfriend, who hoped her husband would eliminate him. The husband reveals that he has attempted to kill her previous lover but failed. He persuades George to take revenge by sabotaging his wife's car. George follows through with the plan, leading to her tragic death. To his horror, he later learns the stranger was actually her former lover, who had manipulated George to settle his own score.