When Lleyton Hewitt and Joachim Johansson walk in to the Arthur Ashe stadium on 'Super Saturday' it will not only be a U.S. Open final place at stake, there will also be bragging rights at the Hewitt dinner table.

This year's surprise package Johansson is the long-term boyfriend of Hewitt's sister Jaslyn and regularly spends Christmas with her family in Adelaide.

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Jaslyn was courtside when the 28th seed stunned defending champion Andy Roddick with a five-set victory on Thursday to clinch a meeting with her brother.

"She can't choose her brother but she can choose her boyfriend, so I hope she'll be shouting for me," the 22-year-old Swede told reporters after beating Roddick in a match that contained 64 aces.

He said Jaslyn would watch the match from a private box, hidden from the gaze of the cameras, which is probably a good thing as her emotions are likely to be put through the mincer.

Johansson showed plenty of Hewitt's fabled guts against Roddick, holding firm in front of a partisan crowd in a tension-filled fifth set, he even gave a few of the Australian's trademark "Come On's" after big points.

Afterwards the unassuming Swede, who was supposed to be playing golf with his father in Scotland this week, said he had learnt a lot from the man he will try and stop on Saturday during their regular practice sessions in Australia.

"He's a great player, he gives 100 percent on every point," said Johansson. "I've developed my game playing with Lleyton because he gets so many balls back, it makes me work a little more."

HEWITT CRUISE

Hewitt, the 2001 champion, has cruised through to the semi-finals without dropping a set but possesses first-hand experience of what he can expect.

"He has a lot of firepower. I'm sure that him doing some training with me and (coach) Roger Rasheed over Christmas has helped his confidence. His last six months have been pretty impressive."

Johansson won his first ATP title in Memphis in February on the same day Hewitt marked his 23rd birthday with victory in Rotterdam.

Strangely, Hewitt's fiancee Kim Clijsters also won the Antwerp tournament that day.

While Johansson was taking on Nicolas Kiefer in the final, Jaslyn was also celebrating her 21st birthday in Australia to complete a memorable party.

While one semi-final may have more family twists than a soap opera, the other between world number one Roger Federer and Britain's Tim Henman promises to be one for the tennis purists.

Federer, who ended Andre Agassi's hopes in the quarter-finals, is the outstanding player to emerge in recent seasons, winning three Grand Slam titles, two this year.

Victory for the Swiss stylist will make him the first player to win three Grand Slams in a year since Swede Mats Wilander in 1988, and he will start favourite against Henman despite trailing 6-2 in head-to-heads.

Henman has come through three tough five-setters despite starting the tournament with a back injury which left him barely able to walk.

The Briton, still to reach a Grand Slam final despite four Wimbledon semi-finals and a run to the last four at Roland Garros this year, exudes quiet confidence.

"If you give Roger time from the baseline he's got so many shots," said Henman, who turned 30 this week. "I will try to be aggressive and give him less time.

"It's the toughest task in tennis playing him but I've beaten him before and believe I can do it again."