Dundee lost 2-0 in a poor game in their bid to try and stay up. They fell behind after only three minutes when Grieve scored from close range. Dundee tried to attack but looked well off the pace with the Paisley side taking control of the game.
Young keeper Harry Sharp made a wonderful save to deny Main who had placed his header well. A poor half finish with St Mirren leading 1-0.
Second half and Dundee were the better side in the first ten minutes, but soon after Main made it 2-0 and that finished the game.
Dundee made a few changes to try and get back into the game but this failed and three massive points were lost.
Next Up is Hibernian at Home on Tuesday night.
Dundee : Sharp, Kerr, Sweeney, McGhee, Marshall, McGowan (Byrne 65), Adam (c) (Mulligan 60)
McCowan (McMullan 60, McGinn, Rudden (Anderson 73), Mullen. Unused Subs: Welsh (gk), Fontaine, Chapman, Robertson, Daley-Campbell.
Att: 5,564
Referee: David Dickinson