US
Japanese star beat Belgian Minnen 6-4, 6-1 to book second-round
Four-time major champion beat Yulia Putintseva 6-2, 7-6 (7/5) to give her side an early 2-0 lead over Kazakhstan
Four-time Grand Slam champion returns to tennis this season after giving birth
Four-time Grand Slam champion beat Italian qualifier 6-3, 6-1 to reach second round
Czech edged out Japanese star 7-6 (8/6), 7-6 (7/5) in straight sets
This was former world number one's second win from the five matches
Former world number seven defeats Japanese star 7-5, 6-0 in the first round
Czech world number 39 defeats Japanese star 3-6, 7-6 (7/4), 6-4 in second round
Former world number one upsets gallant Korpatsch 6-3, 7-6 (11/9) to win her first match after long break
Coach says former world number one return is best news for women’s tennis