Cardiff City soared to the top of the table as Peter Thorne's powerful second-half header condemned a bottom of the table Mansfield to their eighth home defeat of the season.
But big-spending Cardiff were made to fight all the way by the smallest squad in the division and the Stags almost prevented their fourth successive defeat deep into injury time when Colin Little stretched to meet Wayne Corden's deep cross, but his close-range finish rolled agonisingly wide of the post.
Afterwards Mansfield manager Stuart Watkiss said: "I couldn't have asked anything more of my players. Unfortunately we didn't take our chances and one mistake has cost us dear." Mansfield dominated from the start as an adventurous 3-4-3 formation took City by surprise.
Lee Williamson's 20-yard snap shot flew narrowly wide, Liam Lawrence's piledriver was blocked by Gary Croft and the defender then made another fine last-ditch tackle to deny Little.
The Bluebirds were lucky to survive again when Little appeared to be tripped by the keeper as he raced unmarked into the area.
However the best chance of the opening half fell to City midfielder Leyton Maxwell who somehow scooped his ten-yard shot over the bar.
On the hour the visitors failed to convert three chances inside 10 seconds. First Thorne's close-range shot was blocked by keeper Kevin Pilkington's legs, Grahem Kavanagh's follow- up was cleared off the line by Lawrence and from that rebound Thorne blasted wide.
But 20 minutes from time the striker made no mistake, rising highest to head in Kavanagh's deep cross to break Stags hearts