Hsieh and Peng have 11 WTA-level titles during their partnership, including a Grand Slam and WTA Championships. Huber and Raymond have nine WTA-level titles together, including a Grand Slam and WTA Championships. And all four players have spent time as doubles No.1.
But Hsieh and Peng showed why they are the on-paper favorites here, recording a 6-0, 6-2 victory over the 15th-seeded Americans in exactly an hour. Hsieh and Peng converted on five of eight break point opportunities compared to zero out of three for Huber and Raymond and won almost double the amount of points.
"They are both very good doubles players who have had many great results," Peng said. "Before the match we were really nervous and were trying to figure out a strategy. There were some tough games, and it was 2-all in the second set. Hsieh played really well."
Second-seeded Sara Errani and Roberta Vinci also reached the quarterfinals by virtue of a 7-5, 3-6, 6-3 triumph over Andrea Petkovic and Magdalena Rybarikova. The Italians have now won 14 of their last 15 matches.