STEVEN GERRARD hailed the contribution of 'outstanding' Ianis Hagi as the Romanian made the most of his chance to shine in the Old Firm win over Celtic.

Hagi missed out on a place in the starting line-up against Celtic despite producing a series of impressive performances - and scoring in the wins over St Johnstone and Hibernian - in recent weeks.

But he was called upon at the interval at Ibrox as boss Gerrard had to make a switch when Kemar Roofe was forced off with a quad problem just 45 minutes into his derby debut.

Rangers had struggled to impose themselves on the fixture as keeper Allan McGregor came to their rescue on several occasions with a string of terrific stops to keep Celtic at bay.

And his efforts were to prove crucial as Callum McGregor's own goal clinched victory for the Light Blues and moved them 19 points clear at the top of the table.

The the showing from Hagi was another real positive for Gerrard to take on Saturday and he was pleased to see the playmaker influence the Old Firm encounter.

Gerrard said: "It was on our mind in terms of myself and the coaching staff to make a change because we weren't happy with the front three in the first 45 minutes.

"It was a stroke of luck really - or not luck in-terms of the injury as Kemar has a niggle in his quad which we will have to assess and hope he is back fit.

"But it actually played into my hands to get Ianis onto the pitch and I thought he was outstanding in the second half.

"Ianis takes on information really well and I thought he was really brave to receive the ball in the wide areas.

"Ianis basically produced in the second 45 what we were looking for from our 10s in the whole game. So credit to him, but it is a bit of a blow losing Kemar."