MK Dons 0'¨Wigan Athletic 1
But their first opening-day triumph since 2013 wasn’t achieved without concern, with Callum Elder - making his debut at left-back - controversially sent from the field just before half-time following a late challenge on George Williams.
However, MK Dons conceded their numerical supremacy early in the second period when Scott Wootton was penalised for hauling down Michael Jacobs.
Goalkeeper Lee Nicholls was in outstanding form for the Dons against his old club, pulling off a string of saves to keep the margin at just one.
But he had no answer seven minutes before the break, when Jacobs fed Powell, who waited until the perfect moment to stroke the ball past the goalkeeper and into the far corner.
Stadium:mk is clearly a happy hunting ground for Powell, who scored a brace here four seasons ago to keep Latics on the Wembley trail in their defence of the FA Cup.
At the other end, Christian Walton had relatively little to do as the Latics back four kept their opponents at arm’s length, to the delight of their 1,200-strong fanbase behind the goal.
Looking to bounce back from the disappointment of relegation - and aiming to give new boss Paul Cook a winning start - Latics were almost ahead inside three minutes.
The impressive Jacobs raced down the left flank off Powell’s pass, and his cross was superbly dealt with by Dean Lewington at the expense of a corner.
Dons right-back Williams became the first man to be booked for a late challenge on Elder - rt5hfrtwhich wasn’t to be the last time those men clashed.
A swift break from the Dons saw Ryan Seager try his luck from 25 yards, but it was easily saved by Walton.
Another chance for the home side saw Kieran Agard fire just wide of Walton’s left-hand post.
But Latics were also looking good on the break, with Elder and opposite full-back Nathan Byrne getting forward at every opportunity.
From one of those advances, Byrne’s cross found Ivan Toney, who tried to backheel the ball goalwards, only for a defender to get in a good block.
Great stuff from Jacobs then created the opening for Gavin Massey, who ought to have done better than drag his shot well wide from 12 yards.
The first Latics booking of the season then arrived, and no prizes for it being the combative Sam Morsy, wearing the armband for the first time.
Morsy wasn’t happy with the card, and he was furious again moments later when Williams flicked a free header just over the Wigan bar from a well-worked corner.
At the other end, a Massey volley brought about a comfortable save from Nicholls, but the respite for the Dons was only temporary.
With 38 minutes on the clock, Jacobs led a break and fed Powell, who controlled before firing across Nicholls and into the bottom corner.
That looked to be the for the first half, until Elder miscontrolled the ball in centre-field, and succeeded only in stabbing his foot into the knee of Williams rather than the ball.
It was clearly a foul and probably a yellow, but no-one in the Latics camp - not least the player or his manager - could believe the colour of the card when it came out.
Terell Thomas appeared for the second period, slotting in at left-back, with Powell the man sacrificed further up the field.
But the home side couldn’t make their one-man advantage tell, and it was 10 against 10 before the hour mark when Wootton pulled down the escaping Jacobs as he bore in on goal.
The last half-hour was real end-to-end stuff, with Latics unable to find the second goal that would have secured the points.
Toney’s header from Thomas’ cross forced a superb save from Nicholls, who did just as well to repel an effort from Byrne, up from right-back.
Great footwork by Jacobs saw him skin the last man, only for Nicholls to be out in a flash to smother the shot.
Will Grigg replaced Toney for the final quarter, and he would have appreciated the amount of space both sides were leaving at the back.
Soon after, the ball bounced kindly for Jacobs on the edge of the box, but his shot is easily dealt with by Nicholls.
As the 90-minute mark approached, great skills from Ryan Colclough - on for Massey - saw the ex-Dons loan winger have a shot blocked.
Grigg latched on to the rebound, only for a defender to again get in the way, before Jacobs fired straight at Nicholls - who didn’t deserve to finish on the losing side.