Rangers' cinch Premiership title challenge suffered the earliest of blows with a shock 1-0 defeat by Kilmarnock in the opening day of the season.Michael Beale’s disjointed side had laboured in the first half at Rugby Park and there was no improvement after the break before they were stunned by Brad Lyons’ counter after 65 minutes.The 26-year-old Antrim man pounced inside the box to fire the home side ahead and in the end it was enough to keep the three points in Ayrshire.The defeat was a huge setback for Light Blues boss who has signed nine new players so far.Beale knows the margin for error over 38 games in the traditional two-horse title race in Scotland is slim and there is little time for ironing things out on the training ground – the first leg of their Champions League qualifier against Servette is at Ibrox on Wednesday night.Champions Celtic began their campaign earlier in the day with a 4-2 win over Ross County at Parkhead so there was immediate pressure on the visitors to get the win, but there was a lack of cohesion in both teams, perhaps understandably.Derek McInnes’ side had only four players from last season in the starting line-up – stand-in captain Lyons, Danny Armstrong, David Watson and Lewis Mayo, who was signed on a permanent deal from Rangers after a loan spell.Of Beale’s new boys; Jack Butland, Kieran Dowell, Sam Lammers, Abdallah Sima and Cyriel Dessers made their competitive debuts and Brazilian striker Danilo would come on later.Killie, with four ViaPlay Cup games under their belt already, made it difficult for the Govan side, nullifying most of the threat.In the 28th minute, backtracking Mayo brilliantly took the ball off Dessers' toe as the former Cremonese striker raced through from a Sima pass