The 24-year-old internationalist has signed a four-and-a-half year deal from FC Midtjylland
Martyn Waghorn bagged a brace as Mark Warburton's side cemented their place at the top.
Robbie Neilson's side kept the pressure on second-place Aberdeen in the top-flight table.
Craig Slater's stunning volley proved the difference between the two sides at Rugby Park.
Paul Hartley's men pulled off an impressive result in the Premiership match at Firhill.
Tommy Wright's men have now gone five matches without finding the net.
Peter Houston's side had looked on course to claim three points against title-chasing Hibs.
The attacking midfielder spent six months on loan at the Ibrox club, making 19 appearances.
Derek McInnes' side managed to overcome Mark Reynolds' red card to claim all three points.
The Scot will play Alexander Zverev in the first round of the Australian Open on Tuesday.
Read a full match report of the Ladbrokes Scottish League 2 match between Queen's Park and Montrose at Hampden Park
The Rugby Park side made it back-to-back victories with a 2-1 win over Inverness CT.
Read a full match report of the Ladbrokes Scottish League 1 match between Stranraer and Peterhead at Stair Park
Read a full match report of the Ladbrokes Scottish League 2 match between Annan Athletic and East Fife at Galabank Stadium
The playmaker won a penalty and helped himself to a double in Saturday's win over Partick Thistle.
The Ibrox manager hopes to tie up deals for a "couple of players" in "the coming days."
Rangers have had two bids rejected by the McDiarmid Park club for the 25-year-old forward.
Greg Kiltie opened the scoring for the home side but Ross Draper levelled before the half-time break.
Robbie Neilson's side overpowered the visiting Steelmen by scoring six in the Premiership fixture.
Tommy Wright's men have now gone five games without a goal and couldn't hit the net at McDiarmid Park.