Mészáros started his career with Senec, later FC Jelka and at the age of fourteen years he moved to Bratislava-based Inter.
He made his debut in a pre-season friendly against PŠC Pezinok, replacing Juraj Halenár.
[2] The league season began well for Mészáros, as he made a debut with a splendid assist for Ondřej Smetana, netting the opener in a 3–1 home win against Dunajská Streda.
[3] On 11 March 2012 he scored his first goal for Slovan against Košice in a 1–0 win.
[4] In January 2013, Mészáros was sent to ViOn Zlaté Moravce on a half-year loan to achieve greater playing time.