A hefty performer, with close-cropped hair and a natural exuberance, he made his film debut as the aptly-named fast-food chef Spatch in the wacky children's comedy feature "Good Burger" (1997), directed by Brian Robbins. The helmer tapped Lester to co-star in his next feature, the football-themed drama "Varsity Blues". Here Lester was impressive as the fun-loving, hard-drinking Billy Bob, a gregarious linebacker who suffers greatly at the hands of his brutally demanding coach (Jon Voight). The film proved a good showcase for Lester's talents, giving him opportunity to scale emotional highs and lows, going from a partying star football player to a demoralized and debilitated broken man. In real life, the rigorous scenes on the field left Lester with a dislocated knee.

Although the actor was nearing his mid-20s, he was cast in further high school-set projects, taking a recurring role on NBC's "Freaks and Geeks" and starring as a regular on The WB's "Popular". The latter featured Lester as Mike Bernadino, a high school student in the "in crowd" who was a school athlete as well as an aspiring rapper. Nicknamed 'Sugar Daddy', the character could be as sweet as his moniker suggested, but also had a mean streak, tormenting the have-nots when he felt insecure in his own social standing. Lester managed to keep the hip-hop wannabe character from becoming a farce, especially excelling in episodes that explored Sugar Daddy on an emotional plane. Situations like the character's expulsion from the wrestling team because of excess weight, his disappointment at being stood up by his partner in an Internet romance and his confusion over the battling affections of Nicole (Tammy Lynn Michaels) and Mary (Leslie Grossman) showcased Lester's abilities and won over the audience. In 2000, "Popular" won a Teen Choice Award and Lester's enthusiasm was among the more memorable moments in the televised ceremony.