The visitors started well and Charles Dunne twice went close, hitting the post and firing just wide. But it was Cobblers who broke the deadlock in the 24th minute when Akinfenwa powerfully headed home a Chris Hackett cross at the far post.
Dunne headed wide from Dean Morgan's cross but Akinfenwa went close to doubling Northampton's advantage from close range.
But Wycombe stepped up a gear after the break and Morgan went close to an equaliser when he headed into the side-netting.
And the miss proved crucial in the 61st minute when Akinfenwa doubled his tally from the penalty spot after substitute Clive Platt was upended in the box by Dave Winfield.
Northampton increased their lead in the 65th minute from a quick break when Lewis Horby, Ben Harding and Akinfenwa combined to set up Hackett who scored with a fierce drive.
Joel Grant reduced the arrears in the 72nd minute from the penalty spot after East fouled Dunne but the woodwork denied Akinfenwa his second hat-trick of the season when he headed against the bar. Dunne was again out of luck late on when Lee Nicholls saved well as Wycombe looked to get back into the contest.