Celtic and Rangers both started the new SPL season with three points, but Aberdeen are the early leaders.
Paddy McCourt seized an early chance to prove he can fill Aiden McGeady's boots as his superb strike earned Celtic a 1-0 win at Inverness.
The winger was handed the left-wing berth 24 hours after McGeady completed his £9.5 million move to Spartak Moscow and he repaid Neil Lennon in style in the 56th minute as Celtic recovered from a slow start to produce a commanding second-half display.
McCourt beat three men before finishing brilliantly in a goal reminiscent of his solo efforts against St Mirren and Falkirk last season, although he paid the price as he suffered a head knock that ended his involvement.
James Beattie helped Rangers begin their defence of the SPL title with a 2-1 win over Kilmarnock but failed to mark his debut with a goal. Kenny Miller and Steven Naismith were both on the scoresheet for the Scottish champions before Jamie Hamill pulled a goal back from the penalty spot as the season opener at Ibrox ended 2-1.
Paul Hartley scored three penalties in a dream debut to give Aberdeen their first opening-day home win in 16 years with a 4-0 defeat of a poor Hamilton Accies at Pittodrie.
The former Bristol City and Celtic midfielder netted twice from the spot in the first half after winger Sone Aluko had been fouled in the penalty area by first Simon Mensing and then Jack Ross.
Defender Zander Diamond added a third six minutes after the break with a clinical finish to put the result beyond doubt before Hartley sealed his hat-trick from the spot after 65 minutes following a foul by Ross on Chris Maguire.
St Johnstone striker Sam Parkin scored a goal on his debut to keep Hearts' new signings in the shade as the sides drew 1-1. The former Walsall forward levelled on the stroke of half-time after Calum Elliot headed the hosts in front just seconds earlier.
Jon Daly salvaged a point for Dundee United with an 89th-minute strike at St Mirren in a 1-1 draw. The United striker was alert to net a loose ball from close range at the end of a match in which his side had enjoyed the majority of chances.
They had fallen behind on 73 minutes when new St Mirren signing Sean Lynch marked his debut by scoring the opener following a corner.