Wednesday were held to a 1-1 draw at fellow strugglers Brighton while Grimsby fell to a 1-0 defeat to Walsall at Blundell Park.
An unfortunate own goal from Coventry goalkeeper Gary Montgomery on 51 minutes was enough to give Stoke all three points at Highfield and move them closer to safety and in the process end Wednesday's and Grimsby's survival hopes.
Brazilian striker Junior hit the only goal of the game at Blundell Park front two minutes after the break to condemn Paul Groves' side to the Second Division.
Wednesday went down despite earning a 1-1 draw at the Withdean Stadium.
Grant Holt gave Wednesday the lead after 16 minutes but Bobby Zamora levelled from the penalty spot on 57 minutes to keep Brighton's hopes alive of avoiding the drop.
Portsmouth moved back to the top of the table with a 3-0 win over promotion-chasing Reading at Fratton Park.
Vincent Pericard celebrated his return to the starting line-up with a first half brace (19, 45) to put Pompey in firm control.
Svetoslav Todorov wrapped up the win for Pompey with the third on 71 minutes.
Wolves secured their play-off place with a superb 3-0 win over Norwich to end any hopes of the Canaries making the play-offs for the second successive year.
Second half goals from George Ndah (52), Dean Sturridge (74) and Kenny Miller (90) were enough to give the visitors all three points and lift them into fourth spot.
Nottingham Forest maintained their place in the play-offs with a 2-0 win over Burnley at the City Ground.
Michael Dawson gave Forest the lead 15 minutes from time and David Johnson wrapped up proceedings with the second in the dying seconds.
Rotherham dented Ipswich's promotion hopes with a late 2-1 win at Millmoor
Pablo Counago maintained his rich vein in form firing Ipswich in front on 31 minutes.
Rotherham turned the game on it's head with two goals in the last five minutes from John Mullin (85) and Mark Robins (87) to leave Ipswich's promotion hopes hanging by a thread.
Watford ended Derby's good run of form with a 2-0 win at Vicarage Road.
On-loan striker Michael Chopra fired Watford in front on 18 minutes with a superb volley for his fifth goal in four games for the Hornets and Neal Ardley made sure of the win with the second five minutes from time
Gillingham ended their run of six games without a win with a narrow 1-0 victory over Bradford.
Paul Shaw netted the only goal of the game for the home side just before the half hour.
Millwall continued their recent upturn in fortunes with a thrilling 3-2 win over Crystal Palace in their London derby at the New Den.
Dougie Freedman fired the visitors in front on 22 minutes, but Neil Harris levelled from the penalty spot after 39 minutes and Mark McCammon put the hosts in front four minutes later.
Palace replied to level things again on 49 minutes through an unfortunate own goal from Andy Roberts against his old club.
Tim Cahill netted the winner for the home side 16 minutes from full-time
Wimbledon got back to winning ways after the weekend defeat to Stoke with a comfortable 2-0 success over Preston courtesy of a two goals from top scorer Neil Shipperley.
Shipperley fired the hosts in front on the hour mark and he doubled the lead five minutes later with his second of the game.
Click on fixture for full match summary
Brighton v Sheff Wed
Coventry v Stoke
Gillingham v Bradford
Grimsby v Walsall
Millwall v Crystal Palace
Norwich v Wolverhampton
Nottm Forest v Burnley
Portsmouth v Reading
Rotherham v Ipswich
Sheff Utd v Leicester
Watford v Derby
Wimbledon v Preston
