On his new role as caretaker manager Ainsworth said,
"It's all been very sudden but the boys are as tight as ever and and it showed tonight.
"I've got a taste for it. It's something I want to pursue in my career but I'm just taking it game by game.
"If I'm still in charge on Saturday I will take the team to Ipswich. I've had no indication, my only focus is on QPR winning games.
"There will be discussions on players from the parties, I'll put my case forward for players and other people put their case forward for players - and then the final input is mine on the pitch," he added.
"People might have opened their eyes at the changes tonight but the main thing is QPR have won this game 1-0 with 10 men.
"The investment in this club is massive and people are interested in their investment and want to know what's going on.
"I'm happy to be in those meetings and discussions about players, but on a Saturday it's me in the dug-out."
Birmingham were disappointed with their performance.
"It was a great start, we looked dangerous but that was about the sum total," said manager Alex McLeish.
"I'm disappointed we didn't put more pressure on them with 10 men but they had a bit of a cause.
"But the disappointment for me was the performance level. I can take a defeat but we had too many players off the boil."