GLASGOW, Sept 30 (Reuters) - Hearts had to soak up intense pressure before securing a 3-1 win at St Mirren on Sunday in th e Scottish Premier League. They grabbed the first-half opener against the run of play when Andy Driver slammed a lot shot into the net after 41 minutes after a Michael Stewart corner had ripped through a clutch of players. Hearts made it 2-0 with a disputed penalty early in the second half after Stewart went down under a challenge by St Mirren defender David van Zanten. Ex-Manchester United midfielder Stewart took the award himself to double Hearts lead after 55 minutes. St Mirren surged back with Mark Corcoran heading into the net in 78 minutes. However, Hearts secured the points with a third from Lithuanian striker Andrius Velicka who squeezed a near post shot past keeper Chris Smith in 83 minutes. Champions Celtic top the SPL standings on goal difference after beating Dundee United 3-0 on Saturday with a hat-trick from Australian striker Scott McDonald. They have 19 points from eight games, the same as rivals Rangers who were held to a 1-1 draw at Motherwell.