Sam Nicholson scored the decisive goal at Tynecastle after the visitors dragged themselves level from trailing 3-1. New signing Juanma Delgado got off to the perfect start by netting four minutes into his league debut before Jamie Walker doubled the hosts’ lead after the break. Simon Lappin pulled one back but Hearts restored their two-goal cushion through Callum Paterson.
Saints refused to give in and scored twice in three minutes through John Sutton and Irish striker Graham Cummins, but Nicholson grabbed the winner in the 80th minute.
In Sunday’s other match, Kenny McLean netted his third goal of the season as Aberdeen began their domestic campaign with a 1-0 win over Dundee United.
Fresh from giving his side a Europa League lifeline with an away goal in Kazakhstan, the former St Mirren midfielder looped a backward header in off the bar in the 83rd minute to give his team all three points.
On Saturday, Celtic began their title defence with a 2-0 home win over Ross County, but not without cost or controversy. Leigh Griffiths opened the scoring from the spot after only four minutes, but then hobbled off with an injury which could leave him struggling for the second leg of the Champions League third qualifier against Qarabag in Azerbaijan on Wednesday.
Midfielder Stefan Johansen doubled Celtic’s lead in the 35th minute after referee Willie Collum had angered the visitors by only showing Parkhead goalkeeper Craig Gordon a yellow card for a ’last man’ challenge outside the box.
Gordon went on to make a couple of good saves but Celtic were worth their win.
Motherwell won away at Inverness through Wes Fletcher’s debut strike, Hamilton and Partick Thistle finished scoreless, while Dundee won 4-0 at Kilmarnock.