The Czech had won their only previous match at last year’s French Open but Konta is an altogether different prospect these days and broke for the third time at the start of the second set.
Radwanska also caught the eye in a 6-4 6-0 win over Monica Puig, while home favourite Daria Gavrilova overcame Kristina Mladenovic in a thriller to reach the fourth round of a grand slam for the first time.
Her opponent has also been in good form but Allertova was wearing heavy strapping around her left thigh and, whether fully fit or not, never really gained a foothold in the contest.
The Czech had previously beaten Konta at the French Open a year ago but it is a measure of how far the Briton has come that she encountered so few problems inside a packed out Hisense Arena.
Kasatkina raised rambunctious cheers from sympathetic fans in the terraces when she prised a game in each set but Williams finished full of running, closing out the match when her frazzled opponent pushed a forehand wide.
Konta made her first major breakthrough at last year’s US Open when she beat Spain’s Garbine Muguruza in the longest women’s match in history at Flushing Meadows. I thought she played really well at Wimbledon.
Konta was unable to make it a double success as she and Heather Watson lost the battle of the Brits with Jocelyn Rae and Anna Smith winning 6-2, 6-3. Williams wasted no time Friday, beating 18-year-old Daria Kastkina 6-1, 6-1 in 45 minutes, and maybe the outfit helped. The victor of that match next plays either former U.S. Open champion Marin Cilic or Roberto Bautista Agut.
So says Williams, the No. 1-ranked player who is baring her midriff and naval ring at this year’s Australian Open.
Djokovic said the speculation was getting out of control.
The 17-time major victor and third seed won 6-4, 3-6, 6-1, 6-4 in two hours, 40 minutes under the closed roof on Rod Laver Arena and will face Belgium’s 15th seed David Goffin in the next round.
“Yeah, an impressive player”, said Sharapova.
Tournament officials said play would not be possible on outdoor courts until at least 2:30 p.m., and the rain was still falling at Melbourne Park. Next up for Sharapova will be No. 12 seed Belinda Bencic, who outlasted mother-on-tour Kateryna Bondarenko, 4-6, 6-2, 6-4.
Defending champions Novak Djokovic and Serena Williams were set to play night matches Friday.
Serena Williams of the US hits a return to Caroline Wozniacki of Denmark during the women’s final match on the fourteenth day of the 2014 US Open Tennis Championship at the USTA National Tennis Center in Flushing Meadows, New York, USA, 07 September 2014.