The visitors may have already been crowned champions prior to the clash, but there was a sharpness about Mackay's men which suggested they wanted to end their glorious campaign on a high.
Substitute Fraizer Campbell opened the scoring yet goals from Nick Proschwitz and Paul McShane put Steve Bruce's Hull side in front.
Cardiff captain Andrew Taylor was sent off before the hosts were awarded an injury-time penalty yet, as dozens of fans spilled onto the pitch thinking the promotion race was over, Proschwitz's spot-kick was saved and the Bluebirds raced up the other end to get a penalty of their own which substitute Nicky Maynard converted.
A 2-2 draw eventually proved enough to send Hull into the top flight alongside Cardiff after a agonising wait for Watford's failure to be confirmed.
"There's no way I wanted to lose the game and I don't think we deserved to lose the game," Mackay said.
"In Nicky Maynard, Fraizer Campbell and Rudy Gestede I've got three strikers on at the end trying to win the game. But I don't think Steve expects anything different. Steve didn't expect any favours from me and didn't get any. You see his team fighting to the end."
Cardiff more than played their part in an incredible contest, which left both managers drawing comparisons with Brentford's League One clash against Doncaster clash last week.
Mackay added: "I thought the Brentford thing was crazy last week but a sending off, two penalties and a pitch invasion in the space of five minutes is certainly something I've never experienced before but, thankfully, we got the goal back which I think we thoroughly deserved.
"We got off the pitch and allowed Hull to have their day, because this is Hull's day. We got a point and got out of here but congratulations to Steve Bruce and Hull."
- Sports & Recreation
- Fraizer Campbell
- Steve Bruce
- Nicky Maynard
- Nick Proschwitz