That is a terrific win. Last time I saw Ilhan play (I had to go back and check my match report) was QR2 in Marseille ATP in 2015 where he beat Dan Smethurst. He just looked rock solid in all departments of the game.
So congratulations to Felix and good luck for his SF later.
Felix will join fellow junior Arthur Fery on 7 ranking points wef 14/12, in the 1100s in the rankings, GB #34 and 35, or indeed I think actually joint #34 with the same number of tournament MD appearances (8).