Striker Aguinaldo scored with almost the last kick of the match to give the home side victory at Calulo, in the Kwanza Sul province.
Libolo, Angolan champions for the last two seasons, are among three debutants in the group phase this year.
Fellow newcomers AC Leopards of Congo held hosts Orlando Pirates of South Africa to a goalless draw in Soweto on Saturday in Group A.
The two other matches scheduled for the weekend were postponed.
The Egyptian derby between Al Ahli and Zamalek in Group A was moved to Wednesday with the venue changed to El Gouna after security officials refused permission for it to be held in Alexandria on Sunday.
Political turmoil in Egypt, where Islamist President Mohamed Mursi was ousted earlier this month, has brought all other football to a halt.
The Group B match between Coton Sport of Cameroon and Ivory Coast's Sewe Sport was postponed while the Cameroon federation is suspended by FIFA because of political interference in their recent elections.
The top two teams in each group advance to October's semi-finals.