Cardiff manager Malky Mackay saluted his team's character as the Bluebirds moved seven points clear at the top of the Championship with a 1-0 victory at Birmingham.
Mackay's men made the perfect start to 2013 thanks to Joe Mason's first half goal on Tuesday and look well on course for promotion to the Premier League after several near-misses in recent years.
Mason netted his fifth goal of the season in the 41st minute, following up to tap home from close range after Jack Butland's parried save from Craig Conway had taken a fortuitous bounce.
His strike secured Cardiff's first win at St Andrew's since 1966 and their first league double over the Blues in 46 years.
"It was a tough team we played and we knew we had to battle and fight for everything we got," Mackay said.
"We are now seven points clear at the top but it is just about making sure about the game you are in and keep chalking them off.
"It has been a tough period but we have the momentum and consistency which I am delighted about."
Second placed Hull stretched their unbeaten run to eight matches but their 0-0 draw at Blackpool gave Cardiff a significant cushion at the top.
Crystal Palace climbed to third place -- two points behind Hull -- after a 3-1 win over Wolves at Selhurst Park.
Ian Holloway's side raced into a three-goal lead as Brazilian midfielder Andre Moritz scored with a pair of stunning free-kicks either side of a Yannick Bolasie strike.
"The free kicks summed up the day," Holloway said. "I had a chat with Andre in the week. He didn't have a pre-season but has shown what he is capable of."
Sylvan Ebanks-Blake hit a consolation for Wolves, but Stale Solbakken's side have lost four of their last five matches and their boss conceded they face a relegation battle.
"The players who are here are the ones who must take responsibility. We're in deep s**t at the moment," Solbakken said.
"It's my duty to find out why and I won't blame anyone. We have to dig very deep and don't give any excuses - we are a bad Championship team."
Leicester boss Nigel Pearson hailed Chris Wood as the New Zealand striker marked his debut with a brace as the fifth-placed Foxes thrashed Huddersfield 6-1.
Wood completed his switch from West Bromwich Albion on the morning of the match and needed just six minutes to open his Leicester account before adding his second midway through the first half.
"Chris Wood played a very positive part in what a was a very good team performance," Pearson said.
"His attributes fit the bill for a what we are looking for. He is a team player and works very hard and shows a lot of football intelligence as well."
Watford held onto the last play-off spot despite losing 4-3 to Charlton at Vicarage Road, while Millwall remain in the hunt for a play-off spot after beating Bristol City 2-1 at the Den.
Blackburn's caretaker manager Gary Bowyer ruled himself out of taking charge on a permanent basis despite guiding Rovers to a 3-0 win over Nottingham Forest.
"I'm just giving the club a bit more time and then we'll see what that brings and what happens to myself and Terry (McPhillips)", Bowyer said.
Elsewhere, fourth-placed Middlesbrough slumped to a 3-1 defeat at Derby and Brighton won 3-0 at Ipswich.
Leeds beat Bolton 1-0, Burnley won 2-0 at Sheffield Wednesday and Peterborough enjoyed a crucial 2-1 win over fellow strugglers Barnsley.