Denmark midfielder O'Riley arrived from Celtic this week but lasted only nine minutes of his Seagulls debut, hobbling off with an apparent ankle injury against the EFL League One visitors.

It could leave Brighton head coach Fabian Hurzeler worried, but the performance from the rest of his side left little concern.

Simon Adingra got things going in the first half before Jeremy Sarmiento, Julio Enciso and Adam Webster were on target after the interval in a routine second-round win.

Leicester City also overcame its opponent 4-0, beating Tranmere Rovers thanks to goals from new signing Jordan Ayew, Stephy Mavididi, Wilfred Ndidi and Harry Winks.