Samantha Stosur won her first US Open title on Sunday by defeating the heavy favorite, Serena Williams, in dominating fashion in a 6-2, 6-3 straight sets victory. However, Serena got herself into on-court trouble once again.

Find out what happened and the penalty that occurred.

During the second set of the match, Serena thought she had hit a forehand winner down the line, but was ruled out by the chair umpire. Serena then disputed the point with the chair ump, which ultimately led to yelling and a penalty point being assessed to Serena.

Now this incident comes after two years from a more intense altercation involving Williams and an official who called a foot fault against her. Serena then proceeded to yell and threaten the official. Serena was assessed a penalty in that match during match point, which gave the title to Kim Clijsters.

This victory for Stosur gives Australia its first women's singles title since Evonne Goolagong Calwey at Wimbledon in 1980.