Saints were looking for their 22nd successive win at St Mary's, but an horrendous gaffe from former Poland Under-21 international Bialkowski allowed Blackpool to become the first team to take a point from the south coast in 2011.
The visitors looked set to claim all three points until an injury-time equaliser from Rickie Lambert.
Bialkowski, starting his first league match in two years after regular number one Kelvin Davis was ruled out with a groin problem, looked nervous from the outset.
However, top-scorer Lambert, back from injury himself, fired Saints ahead on the half-hour before Chris Basham headed an equaliser before half-time.
Bialkowski then gifted the visitors a second when he let Callum McManaman's weak shot dribble through his legs and into the net.
It was reminiscent of Massimo Taibi's howler for Manchester United 12 years ago, coincidentally against Southampton, and his only saving grace is that the error probably come too late to make this year's Christmas blooper DVDs.
But his blushes were in part spared by Lambert, who struck in five minutes of stoppage time to salvage a point for his side.
Source: PA
Source: PA