Just minutes before the interval, the former Scotland striker fell over his own feet with the goal at his mercy after failing to control a pinpoint cross from John McGinn.
The Saints' leading marksmen could be forgiven for looking at the heavy surface for an excuse as the game was only given the green light earlier in the day after the referee carried out a thorough inspection of the St Mirren Park pitch.
Despite the underfoot conditions, and driving rain, it rarely affected the fare on show as both sides managed to keep the ball on the deck for long periods of the match.
With the wind at their back Thistle started brighter but they were almost caught on the break in the 15th minute when on-loan Newcastle forward Adam Campbell saw his shot cleared following a mistake by Aaron Taylor-Sinclair.
Thistle's Jordan McMillan was booked in the 17th minute for a two-footed challenge on Jim Goodwin and he was joined in the referee's book by home full-back Jason Naismith for a crude lunge on Kallum Higginbotham.
The tackle resulted in the winger being stretchered off with a serious-looking knee injury to be replaced by substitute Steven Lawless.
The visitors passed up a golden chance to take the lead after 32 minutes, a fine pass inside the full-back by Stuart Bannigan finding Taylor-Sinclair whose cross was flicked towards the back post where James Craigen arrived to blast over three yards out.
St Mirren immediately chanced their luck at the other end and visiting keeper Paul Gallacher had to be alert to save at his near post from Paul McGowan's low effort and McGinn fired just wide from the resultant corner.
After the break McGinn (65) was booked for hauling down on-loan Dundee United midfielder Chris Erskine as he tore down on the home defence.
Scotland U21 star McGinn came close to opening the scoring midway through the second half but his low shot from the edge of the area rattled off Gallacher's post and new recruit Gregg Wylde saw his attempted follow-up blocked by Lee Mair.
Thistle responded by hitting the woodwork themselves, Taylor-Sinclair's long-range screamer clipping the top of Marian Kello's bar on the way over.
At the other end, McGowan broke clear of the Thistle defence but despite looking favourite to score, chose to square the ball to Conor Newton whose attempt was blocked.
And as time ran out Thistle players screamed for a penalty claiming Marc McAusland had manhandled Lawless in the box but referee John Beaton waved away their shouts to ensure both sides were rewarded for their endeavours with a point apiece.