Celtic moved a healthy six points clear at the top of the Ladbrokes Premiership with a 2-0 over St Johnstone at Parkhead.

The home side struggled to break down the defensively diligent Saints in the first half of the rearranged fixture.

But seven minutes after the break Callum McGregor powered a drive in from 25 yards before fellow midfielder Ryan Christie curled in a second to ensure a less frustrating second period.

The victory made it 12 home wins out of 12 in the league so far this season and puts pressure on chasing Rangers and Kilmarnock with Aberdeen a further two points behind in fourth place.

Brendan Rodgers' side face Saints at McDiarmid Park on Sunday and again a week later in the William Hill Scottish Cup following a home game against Hibernian next week.

And with four successive wins this year after returning from the winter break, the Hoops look to be building momentum in their bid to make it eight titles in a row.

Saints arrived in Glasgow with the best away record in the league but after the 2-0 defeat by Hearts at the weekend, boss Tommy Wright made four changes with midfielders Blair Alston, Danny Swanson, David Wotherspoon and former Rangers player Michael O'Halloran coming into the side.

Rodgers brought in defender Jozo Simunovic for the injured Filip Benkovic with Oliver Burke taking over from fellow loan striker Timothy Weah and James Forrest in for Mikey Johnston, meaning fit-again striker Odsonne Edouard was back on the bench.

The first 45 minutes did little to heat up the freezing fans.

Celtic kept the ball and probed while a well organised Perth team defended in numbers.

The home side's first real attempt on goal came after 13 minutes when St Johnstone midfielder Murray Davidson fouled Forrest at the edge of the box but Christie curled the free-kick just wide of the post.

The game ambled along until a moment of excitement in the 27th minute when Saints keeper Zander Clark made a fantastic save from Scott Sinclair's close-range header from Emilio Izaguirre's cross.

Celtic remained patient in their build-up as they looked for a gap in St Johnstone's sturdy blue wall.

The second half started along similar lines with Saints compact and resolute but two goals in three minutes changed the complexion of the match.

As Celtic again swarmed around the visitors' penalty area, McGregor took it upon himself to fire in a left-footed drive from 25 yards and it sped past Clark and into the corner of the net.

Saints were still coming to terms with that breach when Christie took a Mikael Lustig pass inside the box and curled high past the Saints keeper for number two which allowed the Hoops players and fans to relax.

Wright soon brought on former Celtic forward Tony Watt and Ross Callachan for O'Halloran and Swanson, before Edouard replaced Burke and Weah came on for Sinclair.

Clark made saves from Weah, Edouard and McGregor in the closing stages as Celtic played with less anxiety, knowing the points were secure.