Dennis Cirkin's third goal of the season earned Sunderland a 1-0 win over Cardiff to move them to within four points of the play-off places.
Cirkin had the simple task of tapping in from two yards out after a free-kick from Alex Pritchard had come back off the post. A second successive home defeat for Cardiff keeps them in the relegation picture in 21st.
Having seen relegation rivals Huddersfield fail to hold onto a 2-0 lead at home against Blackburn, ending up with a point from a 2-2 draw in the end, Cardiff hoped to use their home advantage to go back above them.
For Sunderland, it was a case of trying to get back to winning ways after three successive draws and only one win in their last nine league outings. Tony Mowbray made four changes from the side that drew 4-4 with Hull on Good Friday.
The wind played havoc with the pre-match planning and Bluebirds boss Sabri Lamouchi used four substitutes by the 61st minute. Such was his displeasure at the way things were going he hauled off Jaden Philogene and Sheyi Ojo after only 36 minutes to change the shape of his side.
Sunderland were the more fluent team throughout and thought they had taken the lead in the 37th minute when Jack Clarke headed home a cross from the right edge of the box by Pritchard. The linesman's flag saved Cardiff on that occasion as it was ruled out for offside.
The only effort on target from the home side came four minutes later when Sory Kaba rose in the six-yard box to head down and force Anthony Patterson into a low save in the middle of his goal.
Lamouchi made his third change at the start of the second half when he hooked ex-Sunderland striker Connor Wickham and introduced Kion Etete. That added more frontline threat and Etete forced Patterson into a save with a shot from an acute angle in the Sunderland box.
Having weathered an early storm at the start of the second half, Sunderland used the silky skills of Manchester United loan star Amad Diallo to make headway up the right flank. Then they struck in the 61st minute with a goal from a free-kick to finally break the deadlock.
Home right-back Perry Ng picked up a yellow card for a tackle on Clarke and that gave Pritchard the chance to take aim from the left edge of the box. He rifled his shot through the flimsy wall, it hit the left-hand upright and rebounded to give Cirkin the easiest of tap-ins as he followed up.
There was nothing home goalkeeper Ryan Allsop could do after diving full-length to try to stop the shot and he was furious with his defenders for letting the shot get through his defensive wall. The Bluebirds could find no response as they slipped to defeat.
Cardiff City: Allsop, McGuinness, Kipré, Ng, Romeo (Davies 79'), Philogene (Rinomhota 36'), Wintle, Sawyers (Ralls 61'), Ojo (Simpson 36'), Wickham (Etete 46'), Kaba. Subs Not Used: Alnwick, Harris.
Sunderland: Patterson, Cirkin, Batth, Gooch, Diallo, Ba (Roberts 72'), Clarke, Pritchard (Gelhardt 79'), Neil, Hume, Ekwah (Michut 72'). Subs Not Used: Bass, Taylor, Lihadji, Anderson.