Eight teams are fighting to lay their hands on this trophy

In Group A, only South African side Ajax Cape Town have yet to win the biggest prize in African club football.

The top two finishers in the two groups advance to the semi-finals in September and October.

The final of the tournament - known as the African Cup of Champions Clubs until 1997 - will be played over two legs in late October and mid-November.

Aside a whopping US$1million in prize money, this year's winner will represent Africa at December's Fifa World Club Championship in Japan.

BBC Sport profiles the four clubs in Group A chasing a pot of gold and continental football glory.

Enyimba have won the African Super Cup twice

The reigning champions from Nigeria are seeking to rewrite the history book by winning their third successive Champions League title.

Enugu Rangers, Shooting Stars of Ibadan and Insurance of Benin may be the aristocrats of Nigerian football but Enyimba have outshone them all.

Formed in November 1976, they have been crowned Nigerian champions three times in a row - in 2001, 2002 and 2003.

Two African Super Cups in 2004 and 2005, easily make them the most successful club in Nigeria's football history.

Champions League record: Last year, Enyimba became only the second club after TP Mazembe of Zaire (now the DR Congo) to successfully defend their title.

A year earlier, Enyimba had become the first Nigerian winners of Africa's premier club trophy. So their Champions League pedigree is beyond dispute.

Coach: Okey Emordi has been in charge since last year, when he took over from Kadiri Ikhana - who piloted Enyimba to their first African title.

Not many were convinced by his appointment but he forced his critics to eat humble pie when he masterminded the club's second African title.

Star Player: Goalkeeper Dele Aiyenugba played a big part in last year's success, displaying an ice-cool temperament during the penalty shoot-out in the final against Etoile du Sahel.

He will no doubt be a vital cog in the Enyimba machine as they seek to dominate African club football.

The South Africans are competing in the Champions League for the first time in their relatively short history.

They qualified for the group stage after wins over Mhlambanyatsi Rovers of Swaziland, Burkina Faso's ASFA Yennenga and Fello Star Labe of Guinea.

When the club was formed in 1999 as a 'feeder franchise' for Dutch giants Ajax Amsterdam, the owners stated that their intention was to conquer Africa.

This year's Champions League will give them an opportunity to do just that - although they will be hard pressed to advance to the semi-finals.

Champions League record: None. Ajax are Champions League virgins but they did reach the quarter-finals of the old Caf Cup in 2001, losing to Tunisia's Etoile du Sahel.

Coach:

Igesund is a highly respected coach

Gordon Igesund is South Africa's most successful club coach, having won league titles with Manning Rangers, Orlando Pirates and Santos.

Igesund is also not a man short of Champions League experience, coming close with Manning Rangers in 1998 when he took them to within one game of a place in the final.

But the highly-respected coach knows he has his work cut out this year: "There are no bad teams at this stage of the competition. But we are unknowns and that could work in our favour," he told BBC Sport.

Star Player: The 'Urban Warriors' - as Ajax Cape Town are known, have a host of experienced players in their ranks, including new signing Thiery Mouyouma from Gabon.

But the man who holds the key to the team's progress is DR Congo defender Tsholola Tshinyama.

A very cool head enables him to provide stability at the back - something the debutants will need in a difficult group.

Ahly's resurgence has raised hopes of Champions League success

The African Club of the Century won the Egyptian league title last season without losing a single game.

The Cairo-based outfit proudly sit at the top of the African club football rankings and are fancied to go all the way in this year's Champions League.

They were virtually untouchable on their way to the group stage, brushing aside Sports Club Villa of Uganda and Algeria's USM Alger.

Champions League record: Ahly's record in this competition is as good as any. They won the old Champions Cup twice and the Champions League title in 2001.

They also lost to Ghana's Asante Kotoko in the final of the 1983 tournament - so the club is not exactly lacking in continental experience.

Ahly could prove the biggest threat to Enyimba as they go in search of their first continental title for four years.

Coach: Portuguese coach Manuel Jose is the man who led the 'Red Devils' to their last continental triumph in 2001.

"We are on top at the moment but the challenge is to stay there," Jose said.

Jose's reported monthly salary of US$35,000 makes him the highest paid club coach in Africa.

Star Player: Hopes are high that Ahly can go far this year, as they possess a close-knit group of players who can create danger from all over the pitch.

It is a challenge to single out any one player from a squad overflowing with talent, but Abu Treka and Emad Meteib deserve a special mention as their most influential members.

Morocco's Raja Casablanca are three-time African champions

The Moroccan side are one of the most successful sides domestically, with eight league titles to their credit.

Although Raja narrowly lost their domestic title to FAR Rabat, suffering a 2-0 defeat on the final day of the season, they remain a formidable unit.

The Moroccan side overcame Motema Pembe of the DR Congo and Africa Sports of the Ivory to reach the group stages.

Champions League record: Raja have been crowned African kings three times - in 1989, 1997 and 1999. They were denied a fourth title in 2002 by Zamalek of Egypt.

Coach: Frenchman Henri Stambouli took over coach in December last year, replacing compatriot Alain Fiard.

The 43-year-old led Mali to the semi-finals of the 2004 African Cup of Nations in Tunisia.

Star Player: Marouane Zemmama is yet to establish himself as a regular in the Moroccan national squad but he is without doubt an iconic figure at Raja.

He has several youth team caps under his belt, including an appearance at the last Olympic Games in Athens. Zemmama is known as the local Zidane.