Ultimately, a game which could have gone either way hinged on two moments in either half.
Blues goalkeeper Jack Butland pulled off a contender for save of the season in the 11th minute as he incredibly clawed out a header from Owls centre-back Miguel Llera which appeared to have been beyond him.
Just as amazingly, Blues somehow failed to take lead midway through the second half.
An unmarked Nikola Zigic - included in boss Lee Clark's XI having been dropped for Saturday's 4-0 defeat to Watford following his lacklustre efforts in training - failed to anticipate Chris Burke's cross and diverted the ball wide from merely four yards.
Fit-again Marlon King, one of five changes made by Clark, enjoyed a great chance to open the scoring with just seven minutes gone but his attempted lob was collected by Chris Kirkland, who saved from Wade Elliott's long-range effort shortly after.
But it was opposite number Butland who soon produced the stunning stop of the game to somehow keep out Llera's header from Danny Pugh's corner.
Zigic failed to connect with a great headed chance from Elliott's free-kick just before the half-hour mark, before the big man returned the favour in setting up Elliott but he saw his half-volley blocked.
Both Clark and Owls counterpart Dave Jones would have seen the opportunity for three crucial points within their grasp at the break and the second half started with plenty of gusto, although neither side enjoyed a real chance of note until the 68th minute.
Burke sent in an inswinging cross-come-shot from the right and an unmarked Zigic somehow directed it off target from a matter of yards.
The chance further roused Blues, who had started to dominate, and King saw a shot saved by Kirkland. Zigic then failed to hit the target as he headed wide the lively Jonathan Spector's right-wing cross.
Owls substitute Gary Madine then sent Antonio's free-kick wide from just yards out when he really should have done better, with both sides eventually taking a point.