Bosnia and Herzegovina and Great Britain booked their spots in Division A Wednesday night with wins over Norway and the Netherlands respectively.
Both teams won comfortably on aggregate though Great Britain struggled for the second win, getting 14 points and 10 rebounds from Megan Moody in recording a 60-58 victory.
Sonia Reis scored 29 points and pulled in 15 rebounds as Portugal went on to defeat Great Britain 72-54 in the EuroBasket Women Qualifying Round on Saturday evening.
Portugal stormed out to a 26-15 lead, thanks largely to some strong inside play from Reis, and early indications were that the hosts would be in for a long night.
Bosnia-Herzegovina gave Great Britain's women a basketball lesson in the first half and rolled to a decisive 82-51 EuroBasket Division B triumph in Sarajevo.
With both sides having won their opening two Group B games, the contest beforehand had the look of a thriller but soon after tip-off, the hosts stamped their authority on proceedings.
Great Britain coach Mark Clark has warned the rest of Europe his team only scratched the surface of their potential in their 72-66 EuroBasket Division B win in Estonia.
"Any away win in Europe is always huge, especially when it is the first game of the campaign," he told PA Sport.