The visitors proved to be the dominant side in the first half and their opener arrived in the 28th minute, when Tommy Smith crossed for Murphy, who made no mistake with his head in order to notch his fifth goal in three league games.
Things continued to improve for Mick McCarthy's men during stoppage time in the first period, as Sears stole in to add a second before the break with an adroit finish beyond a helpless Henderson.
Murphy's display was a joy to behold in the second half and he completed a brace in the 68th minute following a swift move from Town, which eventually saw their frontman make it 3-0 with a finish that rattled in off a post.
Charlton left any hope of a fightback until the final 10 minutes of the contest, and they almost found a route back into the game through Ricardo Vaz Te, who saw his well-timed header somehow kept out by Dean Gerken in the Ipswich goal.
The attempts from the Addicks inevitably came a little too late, as Town were able to seal the clean sheet and earn a vital victory in their pursuit of a promotion spot in the standings.