Lewis put the finishing touch to a wonderful team move late in the first-half before he profited from good work by Kion Etete and then smashed home a penalty to complete his hat-trick. Here are our player ratings from Town's fourth successive victory...
5. Ali Koiki
Outstanding at left-back and would have been star man on nearly any other occasion. Saved a goal with a brilliant block from McDonald at one end and then charged up the other to lay the ball on a plate for Lewis. So explosive down the left throughout... 9
6. Shaun McWilliams
The role he played in the opening goal perfectly demonstrated his value to this team. Fine tackle to stop an attack before he got his head up and sent Koiki sprinting away. The highlight moment of another excellent showing... 8
7. Jack Sowerby
He was slow to get going but played a central role in giving Cobblers the upper-hand. Knitted together some well-worked passages and often switched the play from side to side. His partnership with McWilliams has really flourished in recent games... 8
8. Jordan Flores
A surprise starter on the right but the absence of Hoskins and Connolly left Brady with little choice. Regularly drifted over the left where he linked with Pinnock and played some clever balls into and over the forward line... 7.5