Cardiff City went five points clear at the top of the Championship after coming from behind to beat promotion rivals Crystal Palace.
Australian international Mile Jedinak put the visitors in front after four minutes, before Craig Noone equalised for the hosts just before half-time.
Substitute Aron Gunnarsson headed home the winner with 17 minutes remaining.
The Welsh side's victory proved even sweeter with news that second-placed Hull only drew at home with Leicester.
It could prove to be a crucial victory for Cardiff, who showed plenty of resolve after going behind.
Eagles captain Jedinak stunned the majority of the sell-out crowd by nodding home his second goal of the season, and things could have gone from bad to worse for the home fans when Wilfried Zaha cut inside and rattled the crossbar.
But the hosts drew level when Craig Bellamy got clear down the left and cleverly pulled the ball back for Noone to gleefully hammer home.
Gunnarsson and Whittingham both went close as the Championship leaders began to dominate after the break, and the Icelandic midfielder got the winner when he converted Bellamy's corner via the underside of the bar.
Cardiff's Peter Whittingham could have doubled City's lead but saw his free-kick tipped onto the bar.
Cardiff manager Malky Mackay:
"It took until the half an hour mark for us to really get into the game and get on the front foot. From then on in I thought we were excellent.
"They got the message at half-time when we had a chat. I asked them their thoughts on where they thought their level of performance could go and they got there.
"They know if they work hard and step on like we did in the second half then we have footballers who can open teams up.
"It is about patience and doing the correct things and that is what they did."
Crystal Palace manager Ian Holloway:
"We started well and ended terribly. I thought we stopped creating chances and in these games you can't do that and you have to keep going. It was as simple as that.
"You know with this crowd like it is Cardiff are going to come back and in the end I am bitterly disappointed in the last 15 minutes because if any side looked like they were going to score a goal it was Cardiff.
"After they scored I don't think my team did what they needed to do, in fact they did worse and not better.
"There was a lot about us that I was delighted with but I just didn't like the way we ended the game. We have got to look at that part of ourselves because that could be crucial come the end of the season."