Germany, Canada and Australia are through to the last eight of the men's tournament, while the USA, China and Germany advanced on the women's side.
Dirk Koehler scored 16 points to lead the German men through as they made it three wins out of three in Group B with a 64-49 victory over Japan.
Japan enjoyed a 20-14 lead early in the second quarter but Germany outscored them 13-5 to take a half-time lead and powered home on a 10-0 fourth-quarter run.
Patrick Anderson was once again the star of the show as Canada improved to 3-0 to advance, handing Poland their first defeat, 83-65.
Anderson piled up 34 points, nine rebounds and 12 assists, with Richard Peter adding 12 points.
Mateusz Filipski had 20 points for Poland.
Shaun Norris poured in 25 points to carry Australia into the next round with a 75-59 victory over Spain.
In a meeting of Group A's two remaining unbeaten teams, Justin Eveson added 17 points for the victors, while Asier Garcia Pereiro had 23 for Spain.
The USA are on the verge of securing their last-eight place after beating South Africa 91-29 in Group A.
Matt Scott had all 21 of his points in the first half, many of them during a 25-0 second-quarter run that ended the game as a contest.
Turkey's Gem Gezinci and Ali Asker Turan celebrated their birthdays with a 65-60 win over Italy.
Great Britain made their first win of the Paralympics look easy as they eased past Colombia 81-41 to put two frustrating opening losses behind them.
Terry Bywater scored 21 points - 11 of them in the first quarter - while Dan Highcock added 15 and Simon Munn and Jon Hall had 10 apiece.
The USA became the first team to go through in the women's tournament as they beat Mexico 67-33 in the morning session.
Rebecca Murray scored 22 points for the defending Paralympic champions and they used strong defence to pile on the punishment for winless Mexico, converting 20 turnovers into 19 points.
Desi Miller added 18 points for the USA, who made it two wins out of three in Group B, while Estrada Bernal scored 10 for Mexico, eight of them in the first half.
Germany and China will join them in the next round after the Germans made it two wins out of two, defeating France 76-32 behind 23 points from Marina Mohnen.
Gesche Schuenemann added 15 and Annika Zeyen 12 for Germany, while captain Angelique Quemener-Pichon had 12 for France. China were not in action but hold the tie-breaker over Mexico.
In the more muddled Group A, hosts Great Britain got off the mark with a 42-37 win over Brazil.
Bouncing back from their defeat to Australia, Britain used an 8-0 fourth-quarter run to turn a 35-31 deficit into a 39-35 lead, turning a tight contest in their favour.
Amy Conroy scored 18 points for Britain.
Janet McLachlan turned in a captain's performance to lead Canada to a 57-50 win over Australia.
McLachlan scored 28 points and grabbed 21 rebounds, while Amber Merritt led Australia with 16 points.