They followed up last week's 2-1 win at Inverness by disposing of Motherwell 2-0 with goals from John Sutton and an own goal from visiting defender Paul Quinn.
Following the unfurling of last season's first division championship flag, the St Mirren fans were given more cause for celebration when they took the lead from the first attack of the match in the 16th minute. David van Zanten gave the ball to Stewart Kean, who forced himself to the by-line and delivered the perfect low cut-back for his on-rushing strike partner Sutton, who blasted the ball home from six yards.
The visitors almost responded two minutes later, but Ross McCormack saw his 20-yard free kick easily held by Saints' keeper Chris Smith.
Saints' midfielder Hugh Murray then sent a ferocious strike from 25 yards just over the crossbar in the 23rd minute.
Four minutes later Kean glanced a header narrowly wide from Simon Lappin's free-kick, and at the other end Richie Foran headed over from Jim Paterson's corner.
Just five minutes after the interval the home side doubled their advantage when Kevin McGowne's powerful downward header from Lappin's corner was helped into his own net by the unfortunate Motherwell defender Paul Quinn.
'Well keeper Graham Smith then had to make a tremendous double save when he clawed out a Sutton lob before recovering to block the close range rebound from Kean, but the visitors were unable to find a way back into the match and St Mirren sent their fans home happy with a comfortable 2-0 win.