Daniel Nardiello put City ahead before Rickie Lambert scored twice - the second coming in the last minute to give Saints victory.
Tisdale said: "It is very disappointing to have got so close to a result against a good team, as it was when we lost here to Brighton in the same circumstances.
"The turning point was when Kelvin Davis made a brilliant save at 1-0, but they are a multi-million pound team and these players make the difference and that was a brilliant save.
"I`m not ashamed of my team, we played extremely well. On another day we could have got something, but we didn't and we have to pick ourselves up and move on to the next game.
"I was happy with 1-0 at half-time, of course I was. It was such an effort to play out there, they struggled with the pitch and we struggled with the pitch, but you have to adapt and play the conditions."
Source: PA
Source: PA