After well more than 100 official appearances he left for Portugal and S.L. Benfica, being an undisputed starter from the beginning and helping the club to the league in 1988–89, while scoring more than ten overall goals in his first stint; also that season, he partnered compatriot Ricardo Gomes in the heart of the Reds' defense.
In the summer Mozer was sold to Olympique de Marseille of France, and faced his former side in the campaign's European Cup semifinals, a 2–2 controversial aggregate exit – again, he rarely missed a game, and helped L'OM to three consecutive Ligue 1 conquests. Subsequently the 32-year-old returned to Benfica, where he still managed to amass more than 75 overall appearances until his departure in 1995, after which he saw out his career in Japan at Kashima Antlers; he was the first player to score in penalty shootouts in two European Cup Finals, in 1988 and 1991. The following players to do this were Frank Lampard and Ashley Cole of Chelsea, in 2008 and 2012.
During roughly ten years, Mozer played 32 times for Brazil. After missing the 1986 FIFA World Cup through injury, he was picked for the 1990 edition in Italy; he was booked in the first two group stage matches (both wins), and did not appear in the round-of-16 against Argentina, a 0–1 elimination.