American tennis player CoCo Vandeweghe has shocked fans with a "petulant" act during a warm-up at a tournament in the US.
The former world No. 9 was playing her first match at the ITF competition in Landisville, Pennsylvania against Georgian Ekaterine Gorgodze.
Vandeweghe won the first set and appeared to be playing comfortably before she changed tack completely.
Down 3-4 in the second set, Vandeweghe seemed to blatantly throw in the towel, barely competing in points as Gorgodze easily levelled the match at one set all.
She didn't make an effort to chase down shots and also grabbed her leg, which was bothering her.