Cardiff moved on to 79 points with six games to play in England's second tier, five clear of second-placed Hull City who were the only one of the top six to win on Saturday.
Hull, who have five games left, beat visitors Middlesbrough 1-0 to move on to 74 points, three clear of Watford with 71.
Hull, who spent two seasons in the Premier League between 2008 and 2010, increased their chances of winning automatic promotion thanks to a finely struck free-kick from Ireland international Robbie Brady after 62 minutes.
Cardiff last played in the top flight in 1962 and, despite only earning a point, their chances of a top-two finish were not damaged as Crystal Palace, Nottingham Forest and Brighton in the other playoff places behind Watford all drew at home.
Palace were held 0-0 by Barnsley, who had to play in the hosts' away kit as the referee ruled before kickoff that their kit clashed with that of the home side.
Forest, unbeaten in nine matches since Billy Davies returned to take charge of the team, stretched that run to 10 by drawing 1-1 with struggling Blackpool who led from the 27th minute after Ludovic Silvestre had put the away side ahead.
But the game tipped Forest's way after Isaiah Osbourne was sent off with 30 minutes to play.
Forest got the upper hand and were eventually rewarded when Lewis McGugan came off the bench to score an 81st minute penalty and secure a point with his sixth goal in as many matches.
Davies said: "Sometimes a point can feel like a victory, sometimes it can feel like a defeat - this time it's the latter.
"I thought we were very pedestrian in the first half. We didn't put enough good crosses into their box, we didn't have enough shots at goal, we didn't put them on the back foot enough," he told the club website (www.nottinghamforest.co.uk).
Brighton stayed in the top six after a 1-1 home draw with Leicester, who remained seventh.
The promotion battle is tight but the fight to avoid the drop is just as fierce.
Blackburn Rovers, relegated last year after 11 straight seasons in the Premier League, face the drop again after losing 3-2 in a thriller at Sheffield Wednesday where they led with a 12th minute penalty from Jordan Rhodes.
Wednesday hit back with two goals from Jermain Johnson, the second a stunning long-range strike, either side of a Leroy Lita penalty to improve their chances of staying up while severely denting Rovers' hopes of avoiding the drop.
Bristol City, who took the lead at Burnley before losing 3-1, are bottom on 40 points and look doomed, but just four points separate the seven clubs above them from Blackpool in 17th to Peterborough who are 23rd.
Blackburn, in 22nd place and having used five managers this season, are in the heart of that dogfight level on 47 points with Peterborough and a point behind Wolverhampton Wanderers, Barnsley and Huddersfield Town.
Wednesday's win over Rovers took them to 50 points, one behind Blackpool on 51.