During his debut campaign, Săpunaru was first-choice right-back as the northerners achieved a double, and scored his first goal in a 1–2 away loss against C.D. Nacional for the League Cup. In early February 2010, he was suspended in Portugal – as his teammate Hulk – following incidents during a 0–1 league defeat at S.L. Benfica, so he returned to his country for a five-month loan and moved to former side Rapid; he did not manage to be played regularly at Porto during that time but, following his return for 2010–11, became a very important first-team unit as they won three major titles, appearing in 40 official games in the process.