Australian Open champion and second seed Sofia Kenin was a high-profile casualty at the Western & Southern Open, where top seed Karolina Pliskova was also upstaged.

Kenin was ousted in straight sets by Alize Cornet, who soared through to the last 16 of the WTA Premier tournament on Sunday.

Staged in New York instead of Cincinnati amid the coronavirus pandemic, Pliskova fell to unseeded Russian Veronika Kudermetova.

Former US Open champion Sloane Stephens, meanwhile, lost in three sets against Caroline Garcia.

CORNET CONQUERS KENIN

Kenin's preparations for the upcoming US Open were dealt a blow following her 6-1 7-6 (9-7) defeat to Cornet.

After receiving a bye into the second round, Kenin was off the pace early as Frenchwoman Cornet raced out to a 5-0 lead in the opening set.

Kenin managed to avoid a bagel against Cornet, who saved a break point en route to serving out the set.

The American – winner of her maiden grand slam crown at Melbourne Park in January – steadied in the second set, forcing a tie-break, but Cornet was not to be denied after one hour, 43 minutes.

PLISKOVA FALLS AT FIRST HURDLE

It did not go according to plan for Pliskova, who was shocked 7-5 6-4 by Kudermetova with this month's US Open fast approaching.

Kudermetova rallied from a 4-1 deficit in the first set and won the last three games of the match to top the 2016 US Open finalist.

The Russian number four – celebrating her third career win over a top-10 player – will now face either 14th seed Elise Mertens or Kristina Mladenovic for a spot in the quarter-finals.

Mertens eased past Rebecca Peterson 6-0 6-2.

STEPHENS SENT PACKING

Stephens – the 2017 US Open winner – suffered a 6-3 7-6 (7-4) defeat against former world number four Garcia in the first round.

Garcia won six consecutive games from 3-1 down in the opening set to lead by a set and a break, though Stephens fought back.

Stephens built herself a 5-3 lead, but Garcia was not to be denied at the USTA Billie Jean King National Tennis Center.

Former world number one and two-time Australian Open champion Victoria Azarenka awaits Garcia.

Elsewhere, 12th seed Anett Kontaveit raced past 2018 French Open and Wimbledon quarter-finalist Daria Kasatkina 6-3 6-1.