The American Windless, who was replaced by James Hamilton at Towers, led Derby's scorers with 21 points but was eclipsed by his close friend Lewis whose 40-point total included nine in overtime. It was Derby's fourth overtime defeat of the season.
Peugeot Birmingham Bullets shrugged off the absence of injured Nigel Lloyd and Tony Dorsey to stay four points behind Towers with a 70-64 win at Newcastle Eagles. Reggie Kirk scored 25 for Birmingham, who took control with an 8-2 run to lead 64-58.
Third-placed Thames Valley Tigers lost ground as Sheffield Sharks' former NBA player John Amaechi continues to make an impact on and off the court.
England international Ameachi, who is considering a legal challenge to the league's salary cap, led their scorers with 28 points in Sheffield's 87-84 win, including the three-point play which snatched an 85-84 lead.
The executive board of the English Basketball Association has rejected the offer to resign by the England coach, Laszlo Nemech, made after the team's 88-61 European championship defeat against Ukraine earlier this month.