TOUGH TASK AHEAD: Serena Williams. PIC/AP

Serena Williams motivates herself as she prepares to take on Dementieva in today's semi-final

Serena Williams is using the global financial crisis as motivation in her Australian Open campaign, threatening herself with a 16-hour flight in economy class if she is eliminated.

The three-time Australian champion was staring down the barrel as Russian Svetlana Kuznetsova served for the match in their quarter-final yesterday but came back to win and advance to the semi-finals.

"I was thinking 'Okay, if you lose, you're going to fly coach (economy) all the way back to Florida," she said when asked what she was thinking as Kuznetsova served.

"How uncomfortable that would be? That motivated me to do a little better.

"I wouldn't allow myself to have the emergency row either. I would be so mad, I would have to sit like the last row, the tightest row. That way I wouldn't do it again."

Williams is the lone non-Russian in the women's semi-final and she knows she will have to play out of her skin to win.

The other semi features Dinara Safina and Vera Zvonareva.

Last one standing
"It's just me against the Russians I guess," said Williams, the only Grand Slam winner in the final four, who is contesting her 15th semi at a major.

Dementieva, 27, has been coming for Williams since 2007, when she turned around a 4-0 losing record against the nine-time Grand Slam champion and won their last three matches. The most recent was a 6-3, 6-1 thrashing in the semi-finals of the Sydney International this month, part of a 15-match winning streak that has made Dementieva the form player on the women's tour.

"She's playing amazing," said Williams, who has complained about being "rusty" at this tournament. "She's really stepped up the level of her game to an unbelievable level.

"I'm going to have to play really well."

TOUGH TASK AHEAD: Serena Williams. PIC/AP