Rangers score two second half goals to beat Celtic in Scotland 's Old Firm Derby . Steven Naismith on target in each half for Rangers who go three points clear at top in Scotland . Celtic have David Mulgrew sent off in the second half for second bookable offence . Old Firm Derby is one of the most hotly - contested in Scottish football .
Rangers score three second half goals to beat Celtic in Glasgow 's Old Firm Derby . Steven Naismith on target in each half for Rangers who go four points clear at top in Scotland . Celtic have Charlie Mulgrew sent off in the second half for second bookable foul . Old Firm Derby is one of the most hotly-contested in world football .