"I am absolutely knackered and I never kicked a ball!" O'Neill said. "I always felt that one goal was going to decide it but we never gave up and that's epitomised our spirit this season. To be honest, even I thought our effort was running out, but we lived to fight another day and, who knows, that might give us the psychological edge.
"My team played fantastic. We were playing against world class players, who showed world class ability. But we stuck manfully to the task and we got something out of the game.
"We looked legless, we looked tired, but we pulled through all that. I can't praise them highly enough, to come and get something out of the game when everything was lost."
His inspirational captain, Steve Walsh, moved into a forward role over the closing minutes a change which paid dividends when he helped to set up Heskey for the equaliser.
"He [Steve Walsh] threw himself up there with 10 or 12 minutes to go, maybe even less. We left ourselves exposed, and there was always a chance of Middlesbrough getting a second goal. But we got one in there," O'Neill said.
His opposite number, Bryan Robson, thought his side had looked comfortable in extra time. "At least we're still in the Cup, still got a European place to go for, but the lads are despondent, yes," he said.Reuse content