Belgian Mertens had made the most of the Italians’ solid start to curl home an effort after 30 minutes.
However, after the midfielder was forced off with injury following a heavy challenge from Sergio Busquets, Barcelona drew level when Griezmann lashed the ball in from close range.
Neither side was able to conjure a winner, Barcelona goalkeeper Marc-Andre Ter Stegen making two smart saves as the first leg finished 1-1 at San Paolo.
The visitors finished with 10 men after Arturo Vidal was shown two quick yellow cards following a tackle on Mario Rui and then pushing his head into the face of the Napoli man during the closing stages.
- Barcelona have progressed from each of their last 19 knockout ties in the Champions League after avoiding defeat away from home in the first leg.
- Since winning their first ever game in the Champions League knockout stages (3-1 v Chelsea in 2011-12), Napoli have failed to win any of their last four games outside of the group stage (D1 L3), with three of those coming against Spanish opponents.
- Barcelona have only won one of their previous nine away games in the Champions League knockout stages (D3 L5), with that lone victory coming against Manchester United in April 2019.
- Gennaro Gattuso and Quique Setién took charge of their first Champions League games tonight – it is the first time in Champions League history that two managers are facing in the knockout stages in their first ever games in the competition.
- Dries Mertens scored his 121st goal for Napoli across all competitions, equalling Marek Hamsik as the joint-top scorer in the club’s history.
- Napoli striker Dries Mertens has netted six goals in the Champions League this season; the most by any player for the club in a single European Cup/Champions League campaign.
- Barcelona’s Antoine Griezmann scored his first away Champions League goal since February 2017 for Atlético Madrid (versus Bayer Leverkusen); each of his previous nine strikes in the competition had been scored in home games.
- Arturo Vidal is the first Barcelona player to be sent off in the Champions League in the knockout stages since April 2011, when Pinto was dismissed against Real Madrid.