Dundee are the day one leaders in the Ladbrokes Premiership after a 4-0 victory over Kilmarnock at Rugby Park.
New signing Rory Loy and last season's leading scorer Greg Stewart both bagged doubles as Paul Hartley's men got off to the best possible start.
Celtic began the defence of their trophy with a 2-0 win against Ross County at Parkhead. Leigh Griffiths scored from the spot in just four minutes and Stefan Johansen added the second goal before the break.
Wes Fletcher's early goal was enough to give Motherwell a 1-0 win at Inverness Caley Thistle, with Scott McDonald missing a penalty for the Steelmen.
Hamilton Accies and Partick Thistle drew 0-0 at New Douglas Park - the Jags played for more than an hour with 10 men after Frederic Frans was sent off.
Hearts play St Johnstone at Tynecastle on Sunday - live on BT Sport at 12.30pm - while Dundee United face Aberdeen at Tannadice, live on Sky Sports at 3.30pm.