Toews played his first preseason game after being sidelined by a lower body injury.
Alex Ovechkin's first goal of the preseason, a power-play tally at 8:17 of the third period, lifted the Capitals into a 4-4 tie.
Dylan Olsen had a goal and an assist for Chicago, which also got goals from Jeremy Morin, Brad Winchester and Brandon Bollig. Antti Raanta made 26 saves through overtime.
Niklas Backstrom, Tom Wilson and Eric Fehr also scored for the Capitals. Marcus Johansson had two assists.
Michael Neuvirth played the first 30:01 for Washington, allowing three goals on 17 shots. David Leggio stopping 16 of 17 shots in relief.