Mertens scored twice to give Napoli a 2-1 win over Roma in Saturday's Derby della Capitale.
After scoring his first goal, for which he dinked the ball over Arsenal loanee Wojciech Szczesny, the Belgium international decided to celebrate by replicating a dog urinating on the corner flag.
The 29-year-old’s form has propelled him to 18 Serie A goals this season as he continues to help Napoli fans forget Gonzalo Higuain's departure to Juventus.
Mertens tweeted post-match that the celebration was devoted to Juliette, his new adopted dog.
He also added the hashtag #FinidiGeorge, in tribute to the former Ipswich star who did the same thing after scoring for Nigeria at the 1994 World Cup. We approve.
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