Another Premier League side, West Ham United, were believed to be leading the race for Onuachu.
This came from the player's agent flew into London for negotiations.
Newly promoted Watford have also been linked with Onuachu.
Arsenal are however in the driving seat and will have no problem paying the 30 million euros transfer fee that Genk have slapped on the 27-year-old.
It is also a well-known fact that Arsenal are Onuachu's favourite club in England.
And with the Gunners likely to offload Academy graduate Eddie Nketiah this summer, Onuachu, who netted 35 goals in Belgium this past season, could be the perfect replacement.
