LISBON, Portugal -- American midfielder Freddy Adu made his Portuguese league debut as an 83rd-minute substitute in Benfica's 0-0 draw with Sporting Lisbon on Saturday.
The appearance crowned an encouraging week for Adu, who scored his first goal for Benfica in Wednesday's midweek Portuguese league cup victory over Amadora.
The 18-year-old, one of the highest-profile players in U.S. soccer, joined the Portuguese team from Real Salt Lake on July 31 after Benfica agreed to a $1.5 million transfer fee with Major League Soccer. He made his Champions League debut for Benfica last month.
Benfica striker Nuno Gomes missed from close range in his team's best chance in the 53rd minute after Sporting goalkeeper Vladimir Stojkovic had saved Rui Costa's shot.
Benfica remained fourth, eight points behind leader FC Porto, which beat Boavista 2-0 and maintained its perfect start to the league season.
Porto's sixth straight victory lifted it six points clear of second-place Maritimo, which visits Amadora on Sunday.
The league's top scorer, Lisandro Lopez, scored for the defending champion in the 14th minute after Boavista goalkeeper Carlos parried Ricardo Quaresma's shot.
The striker doubled his tally in the 73rd from Marek Cech's cross for his sixth goal of the season.
Porto has 18 points, while Maritimo has 12, Sporting 11 and Benfica 10.
Sunday's other matches are: Nacional vs. Naval; Setubal vs. Leiria; Belenenses vs. Pacos Ferreira; and Guimaraes vs. Braga.
Academica hosts Leixoes on Monday.
