Neil Warnock took a major gamble at Ipswich Town and it paid off.
The Bluebirds manager had said Gary Madine would not be fit, but he asked the striker to get involved despite his broken nose.
Madden responded to the call and Warnock said: “Gary Madine was probably not fit to play, but I couldn’t see us getting anything without him and he changed the game.
“It took the pressure of Kenneth Zohore with Gary next to him and I’m sure we will be able to do that again.
“Ours was the biggest result of the night.
“All credit to the lads they’ve been fantastic.”
Madine went on for the second half, replacing Marko Grujic, and City won thanks to Kenneth Zohore’s match winner after 65 minutes.
Cardiff moved four points clear of third-placed Aston Villa with a hard-fought 1-0 win against Ipswich at Portman Road.
Goalkeeper Neil Etheridge kept a third consecutive clean sheet, Cardiff’s 15th of the season, and later tweeted a tribute to Bluebirds fans who made the trip to Ipswich.
Centre-half and captain Sean Morrison went off injured after 40 minutes with Greg Halford taking over, but Cardiff stuck to their game plan and came out on top.
Sol Bamba and Bruno Manga were magnificent at the heart of defence and with blocked Ipswich shots when it seemed the home team would score.
The Bluebirds have now gone seven league games without defeat and now play Bristol City at home on Sunday (Noon).
Cardiff were without Armand Traore, Joe Bennett and Lee Peltier with injuries. Peltier could be out for a month.
Madine and Craig Bryson returned and Zohore scored his first goal since Boxing Day, netting after Madine nodded down a cross.
Ipswich Town: Bialkowski, Spence (Waghorn 78), Chambers, Webster, Carter-Vickers, Knudsen, Ward (Bru 85), Skuse, Hyam (Connolly 73), Celina, Sears. Subs not used: Crowe, Kenlock, Gleeson, Iorfa.
Cardiff City: Etheridge, Morrison (Halford 40), Manga, Ralls, Zohore (Bryson 86), Bamba, Connolly, Mendez-Laing, Damour, Grujic (Madine 46), Hoilett. Subs not used: Murphy, Feeney, Pilkington, Wildschut.
Attendance: 13,205
