Manager Alex McLeish said his Birmingham side may need to fight to the last day of the season in order to ensure their Premier League safety.
Blues lost 2-1 at Newcastle and are only three points above the relegation zone with two games remaining.
"We need a result from the game against Fulham next week," he told the BBC.
"We need to be safe before the last game against Tottenham but, if that is what it takes, then I guess it goes to the wire."
The Magpies took the lead when Shola Ameobi fired in a penalty after Liam Ridgewell was sent off for a deliberate use of the arm to block Fabricio Coloccini's header and prevent a shooting opportunity for Kevin Nolan.
McLeish had few complaints with referee Chris Foy's decision.
"It hit his arm and he on was on the line," the Scot added.
"It wasn't going towards the goal, it was going to the side, but Nolan was probably in a good position to get on the end of it.
"The referee saw the arm going towards the ball and that is a penalty, those are the rules."
However, the Blues boss did think that Newcastle defender Steven Taylor should have been sent off.
"We had a double-whammy. Taylor probably should have been off the park leading with his elbow on Cameron Jerome's cheekbone earlier in the game," McLeish commented.
"We don't want to see that type of thing. Look at my nose and the stitches I have had over the years. That type of challenge is outlawed, but unfortunately the ref didn't see it."
In response, Taylor stated: "Cameron came in at the side as I leapt up for the ball. I spoke to him after the game and explained that."
Victory took Newcastle up to 10th in the table with 44 points. Their manager Alan Pardew said he was already preparing for next season and wanted to bring in players who could "get the fans off their seats".
"Overall, I am absolutely delighted with 44 points because we are in the top 10 again with two games to go and we can dream of a top 10 finish," Pardew reflected.
"I have got the owner investing at the training ground and I have got him investing in players and talking to agents and players, and I want to keep him there, so it was important to get a win today.
"Now we need those three or four players. Newcastle are renowned for getting the fans off their seats, and we know that's probably what is missing and is going to take us beyond where we are at the moment.
"That's the type of player we are looking at and hopefully we can bring one or two of those in to add to what we have got."