Serena Williams was fined $2,000 on Monday for verbally abusing the chair umpire during her loss to Sam Stosur in Sunday’s U.S. Open final, the tournament referee Brian Earley said.Williams, who was still on probation over an in incident at the 2009 U.S. Open, escaped a more severe penalty after officials ruled Sunday’s incident was not a major offense. “Williams’ conduct, while verbally abusive, does not rise to the level of a major offense under the grand slam code of conduct,” tournament referee Brian Earley said in a statement.