ROOKLINE - They sang. They danced. They cheered Lleyton Hewitt and Patrick Rafter to victory.

A group of Australian fans nearly stole the show during yesterday's Davis Cup matches at the Longwood Cricket Club. The boisterous crowd was brought together by Woz Livingstone of Sydney. The 25-year-old, who wore a green feather boa and fishing hat, makes a habit of attending tennis matches with Australian participants. The tradition started at the US Open in 1997 and has taken Livingstone around the world with Tennis Australia helping to organize his trips and supplying tickets at cost.

The group yesterday numbered 22, with most of the fanatics responding to advertisements placed in a youth hostel.

''I came to Boston for the tennis,'' said 27-year-old Anna Coates. ''I've been traveling for 11 weeks. I saw an ad in the hostel for any Australians that wanted to get involved so I went to the Cheers pub and met up with the guys [Thursday night] and got the train here.''

The boisterous yellow-shirted, face-painted, green-haired Australian contingent seated at the south end of the stadium was hard to miss. And even though the shirts carried the slogan, ''This is no tea party - this is war,'' the star-spangled crowd surrounding the group from down under couldn't help but admire their enthusiasm and, on occasion, sing along.

When Rafter neared the end of his straight-set victory over American Jim Courier, they broke out in song, stood on their seats and kicked like a chorus line. To the tune of ''You are my sunshine,'' they substituted the words, ''You are my Rafter. My only Rafter. You make me happy when skies are gray. Please don't take my Rafter away.'' After a winning shot by their hero,
they'd chime, ''That's the way, uh-huh, uh-huh, I like it, uh-huh, uh-huh.''

In his postmatch press conference, Australian upset winner Lleyton Hewitt praised the Aussie fans and noted that team captain John Newcombe was also an admirer.

''It's been great,'' said Livingstone of his tennis sojourns. ''The players love it. They feel it gives them a lift, keeps them focused, keeps them fired up.''

No one could argue with yesterday's results.

Fans feel the heat

With on-court temperatures of 126 degrees, some fans did not have much fun. Medical personnel supervising the site's only first aid tent reported 14 patrons seeking treatment, primarily for dehydration and heat exhaustion. The emergency medical staff cooled patients' core temperatures with water and ice packs. One fan was transferred to Beth Israel Hospital for dehydration and a possible concussion.

Most seeking treatment reported dizziness, a few had shortness of breath, one passed out, and another claimed a rapid heart rate.

''With the large turnout there were a lot fewer problems than expected,'' said Brookline fire fighter David Driscoll.

For spectators heading to the match today, Driscoll and his co-workers advised drinking lots of water and avoiding caffeinated beverages and prolonged sun exposure.

Music to their ears

In between games and sets, fans were treated to a medley of Harvard fightsongs by the university band. The Davis Cup was founded by Harvard senior Dwight Davis in 1899 ... Former president and Yale graduate George Bush seemed to enjoy the festivities despite the musical selections. He sat in thefront row next to Australian prime minister John Howard... Two of Davis'sdaughters were in attendance, along with grandsons Dwight Davis III and JohnDavis... Members of Davis Cup teams past were invited to the matches and honored last night with a dinner at the JFK Library.

Change of plans?

While the Americans plan to stick with Pete Sampras and Alex O'Brien in doubles today, Newcombe is considering a change. He said he had to talk with his team about whether to put Rafter in with Mark Woodforde, bypassing Sandon Stolle. ''We feel good about playing Sandon,'' Newcombe said. ''He is playing really well and he is keen to play. On the other hand, Pat has been out there, he has had a feeling of the court. But it could be a very long doubles match. If it was a three- or four-hour doubles match, and we lost it, it could affect Pat when he has to come up first the next day. We've got to weigh those things and have a talk about it and we are in a fortunate position of having our opponent on the ropes.''