Season 1: Episode 1: Dancing to the Max
Kelly can't decide who to go with to the dance contest at the Max, so she has a dance-off between Zack and Slater. Zack, being the slick kid that he is, secretly has Jessie teach him how to dance. But Kelly picks Slater to be her dance partner, which leaves Zack with his teacher, Jessie, to be his partner. During the dance hosted by Casey, Lisa sprains her ankle and gets dumped by her date, so Screech comes to her rescue. Luckily for Screech, Lisa bouncing around on her bad ankle makes him look like Fred Astaire.