Pro tennis player Serena Williams has been fined US$2,000 for an outburst at the U.S. Open final one day earlier, escaping harsher penalties such as a suspension or a possible ban from future major tennis tournaments.

Williams, who is known for her hot temper and was already on probation for an earlier outburst, lashed out at umpire Eva Asderaki over a call that didn't go her way on Sunday.

In a statement Monday afternoon, the United States Tennis Association (USTA) said that referee Brian Earley had "fined Serena Williams $2,000 following the code violation issued for verbal abuse during the women's singles final" and that the amount of the fine "is consistent with similar offenses at Grand Slam events."

The fine amounts to pocket change for Williams, who earned $1.4 million at the tournament.

The USTA also said that Grand Slam committee director Bill Babcock had conducted a review of the incident and found that "Williams' conduct, while verbally abusive, does not rise to the level of a major offence under the Grand Slam Code of Conduct."

Williams, a 13-time Grand Slam winner, was docked a point for shouting "Come on!" after hitting a blistering on-the-line return. She eventually lost the match in straight sets to Sam Stosur.

The official ruled that William's shout distracted Stosur from hitting a return shot, and she gave the point to Stosur.

Williams initially received a code violation for arguing with the official over the call, but then the situation escalated when she sat down between sets, next to the official's tower.

"If you ever see me walking down the hall look the other way. You're out of control, you're a hater and you're unattractive inside," Williams said during the exchange.

She added: "Who would do such a thing? And I never complain. Wow. What a loser."

After the game Williams took on a gracious demeanor, giving credit to Stosur for playing well and saying that the call probably didn't affect the outcome of the match anyway, since she was simply outplayed.

Speaking to reporters, Williams chalked up her behaviour to the intensity of being in a U.S. Open final.

"I don't even remember what I said, it was just so intense out there," Williams said.

"It's the final for me, and I was just -- I have to go -- I guess I'll see it on YouTube. I don't know. I was just in the zone. I think everyone, when they play, they kind of zone out kinda thing. I don't know, I'll see it later, I'm sure."

Williams was on probation for 2010 and 2011 after she launched a profanity-laced tirade against an official at the 2009 U.S. Open, following a foot-fall call.

At that event Williams lost in the semi-finals to Kim Clijsters, who went on to win the tourney.

Williams was fined $82,500 for the incident and was put on probation for a two-year period that was set to end after the 2011 U.S. Open.

She was warned at the time the fine could be doubled and she could be suspended from other grand slam events if she were to be involved in another "major offence" during her probation.

Williams did not use any profanity during the Sunday outburst.