The win snapped a three-game losing streak.
Lewis entered the NBA directly out of Alief-Elsik High School in Houston in 1998. Just 24, he has become one of the best players on the SuperSonics, averaging 18.6 points and 6.9 rebounds while improving his scoring average in each of his first five seasons.
Lewis was hacked from behind and knocked to the floor by Rockets forward Maurice Taylor, who was called for a flagrant foul. Lewis sank both free throws, giving Seattle a 73-71 lead with 5:14 left and starting a 12-0 run.
Steve Francis scored 15 points on just 4-of-18 shooting for the Rockets, who fell to 0-3 against the Sonics this season.