|Third-seeded Petra Kvitova lost to qualifier|
Aleksandra Krunic 6-4, 6-4 in the third round.
2014 photo by Paul Bauman
Kvitova, who won her second Wimbledon title last month, has never advanced past the fourth round in seven trips to the U.S. Open.
Of the top eight women, only three remain: No. 1 Serena Williams, No. 5 Maria Sharapova and No. 7 Eugenie Bouchard.
It's the third straight year that Kohlschreiber has eliminated Isner in the third round at Flushing Meadows.
U.S. report -- Now it's up to Williams, the two-time defending champion. All other U.S. men and women are gone in singles.
It's the second year in a row that no American man has reached the round of 16. Until last year, that had never happened since the tournament began in 1881.
Notable -- Italians Sara Errani and Roberta Vinci, the top seeds in women's doubles, lost to Jarmila Gajdosova and Ajla Tomljanovic of Australia 6-4, 1-6, 6-4 in the second round. Gajdosova and Tomljanovic are from Slovakia and Croatia originally.
Men's seeded winners -- No. 1 Novak Djokovic, No. 3 Stan Wawrinka, No. 5 Milos Raonic, No. 8 Andy Murray, No. 9 Jo-Wilfried Tsonga, No. 10 Kei Nishikori, No. 16 Tommy Robredo and Kohlschreiber.
Men's seeded losers -- Isner and No. 23 Leonardo Mayer.
Women's seeded winners -- Williams, Bouchard, No. 11 Flavia Pennetta, No. 16 Victoria Azarenka, No. 17 Ekaterina Makarova and No. 20 Casey Dellacqua.
Women's seeded losers -- No. 3 Petra Kvitova, No. 15 Carla Suarez Navarro and No. 30 Barbora Zahlavova Strycova.
Northern California connection -- Sam Querrey, a San Francisco native and former Sacramento Capital in World TeamTennis, was outclassed by Djokovic 6-3, 6-2, 6-2.
Nicole Gibbs, the 2012 and 2013 NCAA singles champion from Stanford, lost to Pennetta of Italy 6-4, 6-0.
Top-seeded Bob and Mike Bryan, seeking their fifth U.S. Open men's doubles title and 100th overall, will meet Bradley Klahn and Tim Smyczek (pronounced SMEE-check) in an all-American third-round match. All except Smyczek played at Stanford, but only Klahn, who's 12 years younger than the Bryans, graduated.
Scott Lipsky, another former Stanford star, lost in the first round of mixed doubles with fellow American Lisa Raymond.
Fast fact -- Isner, ranked No. 15, is the only U.S. man in the top 45.
Quote -- Krunic, on beating Kvitova: “It was an honor for me to be in the same court with Petra. Of course, I didn’t expect to win. I was hoping (to) at least to win a set, but I managed to win a match somehow."