JOHANNESBURG, May 15 (Reuters) - Ghana's Hearts of Oak, who have tasted success in the African Champions League and then the ignominy of early round defeat, are again facing an embarrassing premature elimination for the third successive year.

Hearts were African champions in 2000 but bowed out in the first round of the defence of their title the year after.

Last year, they failed again to make it to the lucrative last eight of the competition, where clubs share in more than $3 million in television and marketing revenue.

The Accra-based side are under severe threat as they head to Angola this weekend for the first leg of their second round tie against AS Aviacao in Luanda.

Hearts, even with Ghana international Emmanuel Osei Kuffour back in their side after his heroics in 2000, have just started their domestic campaign and look to be a pale shadow of the team that stormed to the title three years ago.

They needed an injury-time penalty in their first league match on Sunday to avoid an opening day defeat and were far from convincing in pre-season competition.

The club have also had to seek Ghanaian government assistance to finance their trip to Luanda.

AS Aviacao warmed up for the tie with a 2-0 win over InterClube in Luanda on Wednesday to go top of the Angolan Girabola league.

BUSY FIXTURE

The Champions League match in Luanda is one of 24 games on a busy weekend in all three African club competitions.

The field features four of the clubs that made it to the last eight in the Champions League in 2002 and earned vital cash on a continent where revenue-generating opportunities for clubs are in short supply.

Title holders Zamalek of Egypt continue their defence away in Dar-es-Salaam on Sunday in their second round, first leg meeting with Simba.

Zamalek are strong favourites on their second trip to east Africa after an easy 7-1 aggregate win over Nzoia Sugar of Kenya in the first round last month.

Egypt's other representatives in the competition, Ismailia also have modest looking opposition in the form of AS Port Louis 2000 of Mauritius, where the first leg will be played on Sunday.

African Cup Winners Cup holders Wydad Casablanca are away at Al Hilal of Libya in Benghazi on Saturday, but officials said new Serbian coach Zarko Olaveric, who has been in charge for two matches, would be replaced for the game.

In the CAF Cup, JS Kabylie of Algeria set out in search of an unprecedented fourth successive title with a trip to Senegal to face AS Sonacos in Dakar on Saturday.

JSK had a bye in the first round but go into the weekend's game downcast after their last-gasp failure to win their final league match on Monday and thereby secure the runners-up berth in the Algerian championship, which would have earned them a place in next year's expanded Champions League.

Also playing their first match of the competition are Al Ahli of Egypt, who are on the brink of taking their domestic league title.

Al Ahli are away at Al Nasr of Libya in Benghazi on Friday. All of the return legs of the second round matches will be played on the weekend of May 30-31 and June 1.