Leigh Griffiths scored twice in two second-half minutes to help Celtic to a 4-1 win over Ross County that restores their six-point advantage at the top of the Scottish Premiership.

Australian international Tom Rogic had opened the scoring for Celtic in the 39th minute with a superb strike from the edge of the box after County had spurned a couple of chances at the other end.

Celtic top scorer Griffiths added to his already impressive haul for the season with a curling left-foot strike in the 54th minute before slamming home another 30 seconds after the restart as the County defence floundered.

Tony Dingwall pulled one back for the home side in the 59th minute before Nir Bitton killed off their hopes with a 75th-minute header to finish the scoring.

The win eases the pressure on Celtic manager Ronny Deila who had come in for heavy criticism following his side's 2-1 defeat to Molde on Thursday which has left the Hoops bottom of their Europa League Group.

"I'm very pleased with the three points and I think in the second half we played very good," Deila said.

"We did a good job and scored four very good goals and that's a positive thing."

Meanwhile, Ross County manager Jim McIntyre rued his side's missed chances.

"We've made really good opportunities and we've not been ruthless enough putting them away," the County manager said. "Celtic showed their quality when they had theirs by burying them."

The match, played in torrential rain in the Highlands, took some time to settle but it was Ross County who had the first opportunity to open the scoring when Liam Boyce somehow headed wide from eight yards after being picked out by a Richard Foster cross.

A lack of composure saw County spurn another chance as unmarked midfielder Martin Woods blasted his shot wide as he met a corner at the back post.

Griffiths almost made the home side pay when they failed to properly clear a Rogic cross but he flashed his snap-shot wide.

The Hoops were getting closer and an excellent strike from Rogic saw Celtic make the breakthrough.

The Socceroo took a couple of touches on Mikael Lustig's pass to work the ball on to his left foot before sending a fierce dipping drive into the far corner of the net.

Two quick-fire second-half goals helped Celtic move out of sight of their hosts.

Griffiths got his first in the 54th minute as he took advantage of a slip from Scott Boyd in the box to collect the ball and send a curling shot into the bottom left-hand corner of the net.

The striker sealed his double just 30 seconds after the restart when James Forrest sped past Boyd before cutting the ball back from the by-line for Griffiths to send a composed finish high into the empty net from 12 yards.

Ross County didn't give up and Dingwall hauled one back in the 59th minute. The Celtic defence failed to clear inside the box after some good build-up play from County and Dingwall pounced to rifle a shot beyond Craig Gordon.

Celtic killed off any lingering hopes of a County comeback in the 75th minute as Bitton's glancing header at the front post looped past 'keeper Gary Woods to make it 4-1.