[3] Skomina refereed the second leg of the 2011–12 UEFA Champions League round of 16 match between Arsenal and Milan.

[10] Skomina was unveiled as the referee for the 2015–16 UEFA Champions League second-leg semi-final fixture between Real Madrid and Manchester City at the Santiago Bernabéu on 4 May 2016.

[16] Skomina was selected to officiate in the 2019 UEFA Champions League Final between English clubs Tottenham and Liverpool at Metropolitano Stadium in Madrid on 1 June 2019.

[17] Skomina awarded Liverpool a penalty kick 20 seconds into the match after Moussa Sissoko stopped a cross by Sadio Mane with his arm.

[18] Skomina officiated the iconic 2019–20 UEFA Champions League quarter-final match between Barcelona and Bayern Munich played at the Estádio da Luz in Lisbon, Bayern Munich won the match 8–2, inflicting Barcelona's worst defeat in 69 years.