Powell took his tally for the season to 10 – five in six games – but any hopes of a hat-trick were quickly dashed as Michael O'Neill – Jones' successor as Stoke manager – replaced the two-goal hero as part of a double substitution after he had headed home Joe Allen's cross.
While Hatters boss Jones will not want to remember his first trip back to Stoke since his November 2019 sacking, the game was more memorable for Ryan Shawcross.
Indeed, Stoke's second clean-sheet win in five days was a welcome leaving present for their Inter Miami-bound skipper.
Stoke's talismanic defender received a pre-match presentation the day after the club confirmed his departure following 14 years and more than 450 matches.
City's 1-0 win over Sheffield Wednesday last Tuesday – their first victory of 2021 – left them seven points off the play-off places.
Thanks to Powell's brace and Steven Fletcher's 77th-minute tap-in they achieved back-to-back wins for the first time since early December.
Man-of-the-match Powell fashioned the game's first chance, chipping wide from 20 yards inside the first 30 seconds.
The one-time Manchester United starlet continued to influence proceedings and began the move which led to his opening strike.
Unselfishly, the Scottish striker squared the ball back to Powell to pass into an empty net.
Luton have not beaten Stoke in 10 games and nearly 21 years and were regularly under pressure from a series of home corners.
Glen Rea also collected a caution for fouling Powell while Souttar, Powell and Allen brought saves from Sluga as Stoke hunted a second goal.
Eventually, Powell out-jumped a static James Bree to make it 2-0 and another defensive error was punished by Potters substitute Sam Clucas, who rejected a chance of his own to set-up Fletcher's eighth goal of the campaign.