Conversation so far:
What team did Galis play for in Greece?
Aris of Thessaloniki, Greece.
What position did he play for them?
shooting guard.
was he successful on that team?
He played in the 1986 FIBA World Championship, where he led all players in scoring average, with 33.5 points per game.
Did they win that world championship?
CANNOTANSWER.
did he play for any other teams in greece?
CANNOTANSWER.
What other victories did he have while playing in greece?
Galis next led the Greek national basketball team to the EuroBasket 1987 gold medal.

Question: Who did they win against for the gold medal?
Self-contained rewrite: Who did Aris of Thessaloniki win against for the gold medal in 1987?