Lionel Messi and Cristiano Ronaldo will renew their rivalry in the Champions League group stages after Barcelona and Juventus were drawn together on Thursday.
Barcelona and Juventus, who met in the 2015 final, were paired in Group G along with Ukraine's Dynamo Kiev and Hungarian side Ferencvaros.
Messi, 33, and 35-year-old Ronaldo have been the preeminent forces of their generation, sharing 11 of the past 12 Ballon d'Ors between them, with Barcelona's captain holding a slight edge with six.
Both players have won the Champions League on four occasions.
Current holders Bayern Munich will face Diego Simeone's Atletico Madrid after they were drawn in Group A alongside Salzburg and Lokomotiv Moscow.
The draw, held at a television studio in Geneva, produced several other high-profile clashes.
Premier League club Manchester United were drawn in a challenging Group H featuring last season's runners-up Paris Saint-Germain, quarter-finalists RB Leipzig of Germany, and Turkish champions Istanbul Basaksehir.
Real Madrid, the tournament's most successful club with 13 titles, also face a tough-looking Group B comprising Serie A side Inter Milan, Ukrainian league winners Shakhtar Donetsk, and Bundesliga club Borussia Monchengladbach.
Pep Guardiola's Manchester City have been placed in Group C and will face Portuguese champions Porto, Greek league winners Olympiakos, and French club Marseille.
Premier League champions Liverpool were drawn alongside Dutch title holders Ajax, last season's quarter-finalists Atalanta, and Danish qualifiers Midtjylland in Group D.
Chelsea's new goalkeeper Edouard Mendy will have an immediate reunion with his former club after the Blues were placed in Group E with Rennes, Europa League winners Sevilla, and Russian qualifiers FK Krasnodar.
Meanwhile, Group F will comprise Zenit St Petersburg, Borussia Dortmund, Lazio, and Bruges.
Following the draw ceremony, Uefa announced that spectators will be allowed at European club and national team competition matches, at up to 30 per cent of stadium capacity, where local authorities allow.
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European football's governing body said the decision followed what it described as a successful pilot match on September 24 where Bayern Munich faced Sevilla in the Super Cup in Budapest.
Apart from that game, Uefa has staged all matches behind closed doors due to the Covid-19 pandemic since the restart of football in June.
Uefa said that matches cannot be played with spectators where local authorities do not allow it and that the limit of 30 per cent may be reached if the limit set by local authorities is not lower.
Uefa added that away fans would not be allowed, that social distancing will be mandatory for spectators, and additional precautionary measures such as the wearing of masks must be implemented according to local rules.
"The Uefa Super Cup demonstrated that it is possible for fans to attend football matches in the right circumstances by putting their health and safety first with comprehensive mitigating measures in place," Uefa said.
"[The] decision is a sensible first step which puts fans’ health first and respects the laws in each country," he said. "This decision allows much more local flexibility to deal with admitting fans than was previously the case, always respecting the assessment of local authorities."