Jim Jefferies eagerly welcomed goalkeeper Alan Combe and David Lilley back from injury after his side's midweek capitulation, dropping replacements Simon Ford and Chad Harpur from his 18-man squad.
Gus MacPherson was forced into a couple of changes of his own, with David Barron and Craig Dargo picking up knocks.
Killie almost scored straight from the opening kick-off, with recalled Saints keeper Chris Smith diving at the feet of a rampaging James Fowler to save. The play swept straight to the other end where the home defence looked sluggish, giving Marc Corcoran a chance, but Jamie Hamill slid in to block.
The visitors were having the better of the play, and Craig Bryson was forced to head off his own line from a good Ian Maxwell header in then tenth minute and Billy Mehmet wasted an even better chance in the 17th minute, skying the ball from five yards.
Bryson was penalised by the unpredictable Mike Tumilty for a very soft challenge on keeper Smith to kill Kilmarnock's brightest early opening, but even more surprising was the referee's decision to allow Killie's opening goal.
Garry Hay threw a corner kick on top of the keeper, who was beaten by Hamill's prodigious leap and Invincibile was on hand to knock the ball over the line. The Saints defence was incensed, as there appeared to be more contact from Hamill than on the first occasion.
St Mirren finished the first half strongly with Stewart Kean heading over from Corcoran's precise cross, before Andy Dorman forced Combe into the best save of the half, when he ended a forceful run with a powerful drive which the keeper did well to turn round the post.
Smith was enduring a difficult return to St Mirren's goal and a wayward kick early in the second half fell to Bryson, but he recovered to save the midfielder's long-range effort at the second attempt.
Mehmet squandered another good chance for an equaliser in the 65th minute when Maxwell's long throw was missed by the home defence, but the striker missed the target.
Smith produced his best save of the game in the 69th minute after Paul di Giacomo had sent Invincibile clear, the keeper did well to parry the Australian's well-struck shot.
The home supporters were growing more and more tense as their side soaked up long periods of pressure, but it was then hosts who came closest to scoring.
Saints sub Jim Hamilton sliced the ball across the face of his own goal from Bryson's cross and Invincibile shot inches wide.