On 8 July 2013, Ghilas joined FC Porto on a four-year contract for a fee rumoured to be around €3 million,[8] with a buyout clause of €30m.

[11] His second came 22 days later, as he netted the 3–3 at Eintracht Frankfurt in the UEFA Europa League round of 32 and Porto progressed 5–5 on aggregate; on both occasions, he came on as a second-half substitute.

[13] His maiden La Liga appearance occurred on 12 September, replacing Mike Havenaar in the 59th minute of a 1–1 away draw against UD Almería.

[16] Ghilas was called up to the Algeria national team for the first time in March 2013, for the 2014 FIFA World Cup qualifier against Benin,[17] but did not play in the match.

[18] Ghilas made his World Cup debut on 17 June 2014, playing the last six minutes of a 2–1 group stage loss to Belgium in Belo Horizonte.