On 24 July 2008, Niculae signed a four-year contract with his former club Dinamo Bucureşti. Due to his lack of fitness, Niculae played his first match for Dinamo since his return on 10 August, coming in as a substitute for Gabriel Boștină in a 3–2 win against CS Otopeni, netting the winning goal in the 85th minute. On 30 August, he scored against Universitatea Craiova, securing his team a 1–0 win. The first half of the season was a rather unproductive one, scoring just two goals in nine appearances. On 11 April 2009, Niculae scored his first hat-trick since his return, gaining his team a 4–1 win against Vaslui. Four days later, he scored twice in a 4–2 win against Rapid Bucureşti, helping his team to qualify in the Romanian Cup semi-finals. On 21 April, Niculae netted another hat-trick in a 5–0 win against Gloria Bistriţa. For the last ten minutes of the match, since there were no substitutes left, Niculae replaced the injured goalkeeper Bogdan Lobonţ, managing to keep a clean sheet. Following Lobonţ's long-term injury, Niculae has been appointed captain for the rest of the season. On 17 May, Niculae helped his team to maintain their lead three rounds before the final wrap-up, netting Dinamo's second in a 3–1 win against FC Timișoara. However, three defeats in a row combined with Timişoara regaining their six points back from CAS, saw Dinamo ending on the third place. He ended his first season since his return scoring 12 times in Liga I, and 14 overall.