On 30 July 2013, Barcelona drew 2–2 against Lechia Gdańsk in a preseason friendly; this was Neymar's unofficial debut when he came on as a substitute.[71] He scored his first goal for the club in a 7–1 win against a Thailand XI on 7 August.[72]
Neymar made his competitive debut for Barcelona during the opening game of the 2013–14 La Liga season as a 63rd minute substitute in a 7–0 win against Levante UD.[73] On 21 August, he scored his first competitive goal for the club in the first leg of the 2013 Supercopa de España against Atlético Madrid.[74] On 18 September, he made his UEFA Champions League debut, assisting a Gerard Piqué goal as Barça beat AFC Ajax 4–0 in their opening match of the 2013–14 tournament.[75]
On 24 September, Neymar scored his first goal in La Liga in Barça's 4–1 defeat of Real Sociedad at Camp Nou.[76] On 26 October he made his first El Clásico appearance, scoring the opening goal and assisting the team's winning goal scored by Alexis Sánchez as Barça beat Real Madrid 2–1 at Camp Nou.[77][77] On 11 December, Neymar recorded his first three Champions League goals as he scored a hat-trick in a 6–1 win over Celtic in Barça's final Group H match.[78]