The Poles pushed past a pair of Czechs on Thursday in Prague.
"I'm happy I get to do this one more time," Andy Murray said of his Olympic farewell.
World No. 4 pulls out of Paris.
"Expectations are always high," top-seeded Novak Djokovic said of his Paris Olympic goal.
The three-time Grand Slam champion will finish her career playing for her country.
The Dane announced the news on Tuesday.
Germany's Laura Siegemund and Alexander Zverev are the top seeds at the Olympic mixed doubles event. Draws come out on Thursday.
