Striker Lionel Messi starred for Argentina in their opening Olympic victory after his club Barcelona cleared him to play.
The 21-year-old put the champions ahead and created another goal in the 2-1 win over the Ivory Coast yesterday.
A day earlier, the Court of Arbitration for Sport (CAS) ruled that Barcelona, Schalke and Werder Bremen could recall their players from the Games.
But as the tournament began, all three were included in their national sides.
Barcelona officials confirmed they would not be recalling Messi after he expressed his desire to remain at the Games during talks with the club late on Wednesday.
A smiling Messi brought a huge roar from the Shanghai crowd as his name was announced ahead of the Group A game.
And he bagged a goal with two minutes of the first half left, neatly sidefooting home to put his side one ahead.
The Ivory Coast equalised through Sekou Cisse, who headed in a powerfully seven minutes after the break, but Messi set up an 85th minute winner for Lautaro Acosta.
Schalke and Werder Bremen allowed Brazilians Rafinha and Diego to stay with their squad and both featured in a 1-0 defeat of Belgium.
CAS made its decision on Wednesday, which had initially appeared to rule the trio out of the tournament.
Fifa, which had ruled that clubs must release players aged 23 or under if a nation requests them, said it was "surprised and disappointed" by the decision and appealed to the clubs to let the players take part. - BBC