Institute clinched the Championship 1 title on a dramatic final day of the season on Saturday.
A 2-0 win over basement club Limavady United – coupled with Bangor’s 1-1 draw with Harland and Wolff Welders – saw Stute lift the trophy.
The Drumahoe club’s success also confirmed Ards’ automatic relegation from the Danske Bank Premiership.
Bangor started the day in the box seat, needing victory over the Welders to secure the Championship title, while Stute needed to win their game and wait for the result at Clandeboye Park.
O’Donnell took the pressure off Stute by scoring with his first touch with a back post header, and before half-time a cracking turn, run and shot from McCrudden put the game beyond the Roesiders and placed the pressure firmly on Bangor.
The Seasiders reached the break in their game against the Welders boasting a 1-0 lead courtesy of a 44th minute goal from Jordan Forsythe.
The Welders refused to lie down and slugged it out in the second half.
Their persistence was rewarded when the equaliser came courtesy of Josh Cahoon – who ironically is set to join Ards in the summer.
It wasn’t long before Institute were celebrating their return to the top flight.
Elsewhere, Knockbreda secured third place with a convincing 5-2 away win at Ballyclare Comrades. Donegal Celtic defeated Carrick Rangers 4-3 at Taylors Avenue.
Dundela beat Loughgall 2-1 at Wilgar. Lisburn Distillery finished with a 2-0 win over Dergview and relegated Coagh United earned a 1-1 draw with Larne.
Meanwhile, in Championship 2 Armagh City earned promotion with a 2-0 win over Newington at Holm Park with two second half goals from McParland and Kelly.
The Eagles are now five points clear with a game in hand and three still to play which should be enough for them to clinch the title.
Other Championship 2 results: Banbridge Town 6-0 Tobermore United; Chimney Corner 0-4 Moyola Park; Killymoon Rangers 3-3 Lurgan Celtic; Portstewart 0-1 Queen’s University; Sport and Leisure Swifts 0-2 Ballymoney United.