St Johnstone lead Dundee 1-0 at half time in the Scottish Premiership thanks to a Brian Graham goal in the 25th minute.
Saints piled on the pressure early, and captain Dave Mackay saw his powerful shot blocked in the sixth minute.
After a quiet opening twenty minutes, Simon Lappin nearly diverted the ball into his own net, but Saints keeper Alan Mannus kept the scores level.
St Johnstone took the lead two minutes later when Brian Graham capitalised on a defensive mistake and curled the ball past Scott Bain from the edge of the penalty area.
David Clarkson tried to reply immediately but his shot was blocked, and St Johnstone's Michael O'Halloran missed the target 10 minutes later.