The Brazilian hit his three goals in the space of 13 minutes in the 6-1 win over Celtic to open his account for the Catalan club in European competition
With Lionel Messi still sidelined through injury and Cesc Fabregas suspended, Neymar started in a central role for the Blaugrana and was a constant threat for the Spanish champions.
The Brazilian, who had failed to net in his previous five Champions League appearances, set up Pedro for the second goal before hitting a 13-minute hat-trick either side of the interval as the Catalans ran out comfortable winners at Camp Nou.
The 21-year-old was left all alone to tap home his first following a wonderful team move and waltzed through the Scots' back line for his superb second.
And he completed his hat-trick in brilliant fashion by nut-megging Efe Ambrose before slotting home to become the fourth-fastest scorer of a Champions League hat-trick (some five minutes slower than Lyon's Batefimbi Gomis against Dinamo Zagreb in December, 2011).
Barca's win sees them top Group H ahead of Monday's last-16 draw.