 In the middle of 2008 Gytkjær was called up to the Lyngby first team, taking over from the departed Mads Thomsen who left for Nordsjælland in the previous winter, signing a new contract keeping him at the club till 2010.He got off on to a flying start, scoring 3 goals in 8 appearances in his debut season in the 1st Division, by the 2009–10 campaign Gytkjær had become one of Lyngby's most anticipated talents to come through their renowned youth system.On 2 February 2010 it was confirmed Gytkjær would leave Lyngby when his contract expired in the summer to join Danish Cup winners F.C.