The Latics took a point from their opening Europa League clash on Thursday, their first in a major continental competition, and displayed little fatigue on their return to domestic action.
Shotton and Powell, brought in from Stoke and Manchester United respectively on transfer deadline day, scored in either half to ensure Owen Coyle's men leapfrogged Ipswich in the table.
After making seven changes for the draw with Zulte Waregem in Belgium, Coyle again shuffled his pack by bringing in four fresh faces.
One of those introductions, Jean Beausejour, was in the right place at the right time to flick Luke Chambers' header on to the crossbar early on.
The first goal would shortly follow, but it was to be from a corner at the other end.
Callum McManaman's pace earned it and Shotton stooped to head in Powell's back-post corner to give Latics a 12th-minute lead.
For a side once again playing without a recognised striker, the full-back's first goal since October 2011 was particularly welcome.
It was McManaman who Coyle initially entrusted as his fulcrum but when he drifted out to the right, James McClean found himself bearing down on goal only to delay for too long.
The visitors were far from out of it, though, and Ryan Tunnicliffe and Daryl Murphy were unfortunate to see their efforts cleared away, the second by a brilliant Ben Watson block.
Both David McGoldrick and Paul Anderson headed over from close range and the former flashed another past the post as Latics struggled to deal with their opponents' aerial threat.
But the best chance of the lot fell to Murphy, who forced Scott Carson into a point-blank save before the ex-England stopper pushed Cole Skuse's deflected try wide.
An entertaining first 45 minutes would end with Powell and McClean firing just off target.
Tunnicliffe began the second half by driving into Carson's arms.
However, Coyle's men should have doubled their advantage prior to the hour mark but Thomas Rogne somehow headed wide when completely free in front of goal.
Wigan's sparse options in attack were soon depleted further as McManaman hobbled off after landing awkwardly from a shot he steered wide.
Without McManaman, the onus was on Powell to lead the line and he almost grabbed a second, nodding Watson's free-kick just beyond the far post before James McArthur side-footed wide.
Ipswich laid siege to the Wigan goal in the closing moments but McGoldrick and Tunnicliffe were both thwarted by blocks, while Carson denied Skuse from range.
And Powell, constantly a willing runner, would get his reward and join Jesse Lingard and Federico Macheda in the group of Manchester United loanees to score Championship goals this weekend.
Goalkeeper Dean Gerken made a mess of a long ball, allowing Powell to step in and casually curl the ball in to the corner in stoppage time.