Antonio Colak continued his scoring form with a double as Rangers returned to domestic duties after European euphoria with a comprehensive home win over Ross County.Giovanni van Bronckhorst's side qualified for the Champions League by beating PSV Eindhoven on Wednesday night thanks to a solitary goal from the 28-year-old striker.Back in the cinch Premiership, midfielder John Lundstram opened the scoring in the 24th minute with a deflected 25-yard drive before in-form Croatia forward Colak scored a second in 39 minutes.While Gers defender James Sands was perhaps lucky to escape picking up a second yellow card when the match was goalless and before he was substituted at the interval, Colak added a third just before the hour mark for his seventh goal in seven games and late substitute Steven Davis knocked in a fourth with 10 minutes remaining.The Light Blues moved one point above Celtic, who play Dundee United at Tannadice on Sunday with the chance to reclaim top spot.FULL MATCH DETAILSThere was an air of positivity around Ibrox following the midweek triumph in Eindhoven.Colombia striker Alfredo Morelos - left out of the PSV game due to fitness issues and attitude - was suspended and Gers showed one change, Scott Wright replacing Glen Kamara who was nursing a knee problem.As expected, Rangers grabbed the game from the kick-off against a County side who had Jack Baldwin and midfielder Ross Callachan suspended but it was no blitzkrieg.Winger Ryan Kent fired just over the bar from the edge of the box in the second minute and Staggies keeper Ross Laidlaw denied Gers defender Connor Goldson from close range seven minutes later.Referee Don Robertson ignored County claims when Sands, already booked for a foul on Jordy Hiwula,