Danny Wilson's men rocketed up the Division Two table after coming from behind at Ninian Park.
The Bluebirds took the lead just after the interval through Graham Kavanagh, but a devastating four minute burst from the visitors turned the game on its head.
Scott Murray equalised on 56 minutes, and the midfielder doubled his tally two minutes later, before Lee Matthews struck on the hour mark to seal the victory.
Fellow promotion chasers Stoke City remain in second after a creditable 0-0 draw at Huddersfield, but the biggest losers of the day were Brentford, who dropped to fourth.
The Bees lost 1-0 at Tranmere with Jason Koumas' tenth goal of the campaign on 61 minutes separating the teams.
Brighton looked destined to end the calendar year at the head of affairs, but a last minute equaliser from Lee Collins denied them three points at Blackpool.
Peter Taylor's troops did stretch their unbeaten run in Division Two to 12 matches with the 2-2 stalemate at Bloomfield Road, but they will rue a missed opportunity.
First half goals from Lee Steele and Nathan Jones put the visitors in the driving seat, but Ian Hughes' first goal of the season gave Blackpool hope, which was realised in the dying seconds by midfielder Collins.
Reading remain in the promotion hunt following a 2-0 win at struggling Wrexham. Nicky Forster opened proceedings on 31 minutes and John Salako scored in his third consecutive appearance midway through the second period to put the icing on the cake.
Queens Park Rangers leaped into the play-off places, but they were forced to battle all the way by nine-man Wycombe Wanderers to earn a 4-3 success.
Andy Thomson's 18th goal of the season on 26 minutes set the ball rolling until Steve Brown levelled matters from the penalty spot five minutes later. On the stroke of half-time, Wycombe were given a mountain to climb when both Jermaine McSporran and Danny Senda were sent off.
Kevin Gallen restored the host's advantage on 54 minutes, and Karl Connolly's strike just past the hour appeared to wrap matters up. Dannie Bulman, though, reduced the arrears three minutes later before Gavin Peacock's first goal of the term increased The R's cushion again. Andy Rammell's 80th minute spot kick set up a tense finish at Loftus Road, but Rangers held on.
Oldham ensured Northampton culminate 2001 in bottom place, and boosted their own promotion hopes into the bargain via David Eyres' 80th minute goal at Sixfields Stadium. Cobblers keeper Keith Welch was sent off bang on half-time.
Swindon moved further into mid-table with a 3-1 home victory over Bury. Goals inside the first ten minutes from Andy Gurney and Bobby Howe put The Robins in the ascendency, but Jon Newby pulled one back for Bury. On-loan midfielder Wayne Carlisle settled the nerves with the third goal on 51 minutes.
Wigan failed to make positive progress in the table as they were held 0-0 at home by Bournemouth, while it is now eight games without a league win for Peterborough as they drew 0-0 at Cambridge.
Port Vale inched away from the relegation zone with a convincing 3-1 home triumph over Colchester. Goals inside the space of four first half minutes by Ian Armstrong and Steve Rowland's first ever professional strike handed Vale the initiative.
Steve Brooker extended their advantage on 69 minutes before Karl Duguid netted a last minute consolation for the visitors.
Chesterfield will be thanking Oldham for their 2-1 win over Notts County at Saltergate. Mark Innes and Mark Allott, both of whom are on loan from Boundary Park, grabbed the crucial goals. Innes opened the scoring on 43 minutes, but Nick Fenton equalised just after half-time. It was left to Allott to pop up with the winner six minutes from time.
Click below for match summaries
Blackpool v Brighton
Cambridge United v Peterborough
Cardiff City v Bristol City
Chesterfield v Notts County
Huddersfield v Stoke City
Northampton Town v Oldham Athletic
Port Vale v Colchester
Queens Park Rangers v Wycombe Wanderers
Swindon Town v Bury
Tranmere Rovers v Brentford
Wigan Athletic v Bournemouth
Wrexham v Reading
Click here for Division Two table
