sixth seed petra kvitova eased past her fellow czech opponent, denisa allertova, with a 6—2, 6—4 victory. the two—time wimbledon champion will now face germany's andrea petkovic for a place in the last 32. cani can i be prepared for her? i know how she is playing, we know each other very well, so we will see but it will be another tough battle. the know she likes to put pressure on her opponent as well, playing fast, and that is what i am going to try as well. former wimbledon champion, and number 2a seed, garbine muguruza is out, though. she lost 2—6 6—1 6—3 in the first round to alison riske. the american is ranked 11 places below muguruza, and this is herfirst win at flushing meadows since 2013. for the spaniard, it's the second grand slam in a row where she's been knocked out in the first round. in the men's draw, the 8th seeded greek, stefanos tsitsipas, is out after losing in four sets to unseeded russian, andrey rublev. the 21 year—old didn't have an enjoyable day and he was docked a point during the nearly four—hour encounter for this incident. tsitsipas: i have to ch