Speaking on court after winning the Australian Open women’s singles title on Saturday night, Serena Williams was gracious about her opponent, Justine Henin.

But when she told the Melbourne Park crowd and a TV audience of millions around the world that her victory had been “a real G moment”, she was being less than gracious to her hosts — by ambushing one of their major sponsors.

It may have gone over the heads of many watching in Australia, but to viewers in the US. Williams’ apparent throwaway line represented a massive free plug for her sponsor, Gatorade. The sports drink has recently re-branded its anchor product as “Gatorade G”, placing much greater emphasis on the letter G in its packaging design and promotion. The term “G moment” has been widely used in North America in advertising, competitions and in-game promotions.

Serena Williams is one of Gatorade’s star endorsers,  alongside basketball legend Michael Jordan, New York Yankee Derek Jeter and sprinter Usain Bolt. Not only are these athletes contractually obligated to consume Gatorade while competing and at media appearances, it seems they are also “encouraged” to link the brand to their sporting achievements whenever they get the opportunity.

Williams threw the “G moment” into a post-match press conference at Wimbledon last year but this weekend seems to be the first time it has appeared on-court at a major.

At least Henin knew what to expect when she faced the world No.1, and had a racquet with which to defend herself. But Coca-Cola’s Powerade — which no doubt paid a tidy sum to be an official sponsor of the Australian Open — had no warning and no right of reply.

Gatorade doesn’t pay Tennis Australia a cent, but the value of a mention like that to Gatorade’s parent, PepsiCo, is massive and essentially immeasurable. TV and online audiences for the coverage might be quantifiable, but Williams’ comments linked the Gatorade G brand explicitly to her performance and her victory — that’s the kind of emotional brand association sponsors dream of, and it’s worth untold millions.

Of course, Williams’ last appearance at a Grand Slam tournament was much less G moment and much more F-bomb.

When they finish celebrating, the folks at Gatorade would do well to take a moment to reflect on how lucky they are that Williams was even allowed to compete in Melbourne. In what other sport could a competitor threaten, physically intimidate and abuse an official and get away without a suspension?

After a belated and less than abject apology, Williams was fined a mere $82,500 by the Grand Slam committee for her astonishing on-court behaviour at the US Open last September. That’s a drop in the Gatorade bucket compared to what she earned in prizemoney, and the value she delivered to her sponsors, on Saturday.

Williams’ victory speech also contained another unpaid plug: her first “thank you” was to God. That’s the same God to whom she swore twice that she’d shove an fucking ball down the female line judge’s fucking throat at fucking — sorry, Flushing — Meadows.

God’s marketing people may well be wondering about the value of that endorsement.