Leicester City looked destined to beat Napoli in their Europa League Group C opener, but Victor Osimhen earned the Italian side a point.
In a landmark game for manager Steven Gerrard, Scottish champions Rangers were no match for a clinical Lyon side at Ibrox.
For half an hour, Celtic threatened to race away from Real Betis, only to ultimately come up short in their Europa League opener.
West Ham enjoyed a memorable first appearance in Europe (excluding qualifiers) since 2006-07 as they won in Croatia on Thursday.
Switzerland boss Murat Yakin said Granit Xhaka had a human right to turn down a COVID-19 vaccine, after the captain tested positive.
Manchester United dominated Copenhagen in the last eight of the Europa League but needed an extra-time penalty to advance.