Wigan's James McClean hit the post in response before Diallo crashed a shot off the underside of crossbar as Sunderland pressed for a second before the break.

Moments later the Latics had their equaliser, with Will Keane following up Anthony Patterson's save from Thelo Aasgaard to tap home.

Substitute Stewart added a second from the penalty spot after Tom Naylor's trip on Patrick Roberts, who went on to make it 3-1 with a deflected effort before Diallo added a brilliant fourth.

With results going Sunderland's way they moved into the play-off spots, while a third straight defeat for Kolo Toure's Latics saw them tumble to the foot of the table after Huddersfield beat Rotherham.

Simms, who came on as a substitute to score the winner against Blackburn on Monday to move Sunderland into the top half of the Championship, started against the Latics as Stewart dropped to the bench in one of five changes for the trip to the DW Stadium.

Australia's Bailey Wright made his first Black Cats start since returning from the World Cup, while on-loan Paris St-Germain midfielder Edouard Michut earned his first Sunderland start in a side missing Lynden Gooch and Dennis Cirkin through injury.

Wigan boss Toure made three changes in pursuit of his first win in management, recalling Tendayi Darikwa and Naylor to the starting line-up while handing Ashley Fletcher his first league start.

A superb double save from Jones - using his foot to first deny Diallo before clawing out Ba's follow-up attempt before it crossed the line - proved only to delay the Black Cats from taking the lead as Simms headed in from the resulting corner.

In two thrilling minutes late in the first half, McClean volleyed against the post for the hosts, Diallo was thwarted by the bar from a good position, and Keane levelled with a cool finish.

Four minutes after coming off the bench in the second half, Stewart levelled with a penalty that squeezed in off the foot of the post after Naylor's foul on Roberts, another of Sunderland's second-half substitutes.

Minutes after a heavy deflection saw Roberts add to the advantage, he exchanged passes with Diallo whose swerving effort from outside the box was the pick of Sunderland's goals.

'The fans can dream' - reaction

Wigan Athletic boss Kolo Toure:

"Conceding goals of course isn't great. But trying to score goals when you are losing is part of the game, you have to go for it.

"We are not a team that, when you are losing a game, you just try to defend.

"We want to come back in games, but when you do that, you can lose 4-1 - and that is very tough to take.

"The penalty, in my opinion, was harsh, and I don't think a team like Sunderland needed those kinds of decisions to help them. After that we are chasing the game, and you have to react to that."

Sunderland manager Tony Mowbray:

"We're competing, and the target for this club is still to stay in this league, and to try and compete around mid-table.

"That might be the case come the end of the season, depending on how the squad survives the rigours of the campaign.

"At the moment, we're not dreaming of anything else, the fans can dream of course, because we're in the mix at the moment with loads and loads of other good clubs.

"Lose two games, though, and all of a sudden you're 15th. Win two games, and all of a sudden you're fourth."