Perth, Scotland (SportsNetwork.com) - Celtic extended its winning streak to eight games in the Scottish Premier League on Saturday as goals from Leigh Griffiths and Stefan Johansen propelled the Hoops to a 2-1 victory at St Johnstone.

The result lifts Celtic six points clear of second-place Aberdeen, which visits Hamilton on Sunday, while St Johnstone remains in the middle of the table after sustaining its 11th defeat of the campaign.

Griffiths got Celtic off to a perfect start on Saturday as he scored inside the opening minute after taking a pass from Nir Bitton.

The first half saw both sides create good chances with some end-to-end action, but the teams went into halftime separated only by the early goal from Griffiths.

Celtic snatched a 2-0 lead in the 52nd minute when Griffiths nodded down a chip from Stuart Armstrong that allowed Johansen to fire the ball home from six yards.

St Johnstone got back into the match in the 72nd with a deflected cross that was parried by goalkeeper Craig Gordon into the path of Michael O'Halloran, who hammered the ball into the roof of the net from close range.

The hosts pressed for a late equalizer but were denied twice by some good goalkeeping from Gordon, who first kept out a header from Brian Graham before stopping Dave Mackay's volley.

Inverness held off St Mirren, 2-1, to remain in third place, last-place Ross County notched a 3-2 home victory over Motherwell, Paul McGowan's goal in the 90th minute clinched a 1-0 win for Dundee over Partick Thistle, while Kilmarnock overcame a 2-1 halftime deficit against Dundee United to win 3-2 thanks to second-half goals from Christopher Johnston and Sammy Clingan.