It was an afternoon of firsts for St Mirren as they beat Hibs 2-1 thanks to Ian Maxwell's first goal of the season and Garry Brady's first goal for the club.
The result means that St Mirren have now beaten the Easter Road side twice in the league this season and, in a double-whammy of trouble for the Edinburgh sides, move above struggling Hearts in the SPL table.
The opening goal came out of the blue as Maxwell sent a flighted cross goalwards only to see it strike the underside of the bar and end up in the corner of the goal behind a stunned Yves Makaba-Makalamby.
From then on all of the play was in favour of the home side. Brady had a great chance to double the lead just after the half-hour mark but his right-footed shot from 25 yards out went narrowly over the crossbar.
Hibs looked desperate, unable to play their usual brand of football, they resorted to booting long balls up the field.
Their best chance came from Mickael Antoine-Curier who tried his luck from long range and a tight angle but sent his effort over the crossbar.
But St Mirren did manage to add another goal to their tally before the break when Mason netted after good play by Stewart Kean.
In an effort to buoy his flagging side, caretaker boss Tommy Craig made a change at the start of the second half bringing off the ineffectual Clayton Donaldson and giving a first outing of the season to teenager Damon Gray.
Hibs immediately began to look brighter as Gray linked up well with Antoine-Curier but the frontmen were lacking good service from behind them.Guillaume Beuzelin was having an uncharacteristically poor match producing some terrible, unreachable passes.
The visitors lacked urgency in the second half and it was again St Mirren that looked the more likely to score. Billy Mehmet went close but put his shot too close to Makaba-Makalambay.
Eventually Hibs did make the breakthrough, but it was too little too late as Antoine-Curier back-heeled the ball into the net after rounding the keeper in the 89th minute.