The 2007 AFC Champions League was the 26th edition of the top-level Asian club football tournament and the 5th edition under the current AFC Champions League title.
A total of 28 clubs were divided into 7 groups of four, based on region i.e. East Asian and Southeast Asian clubs were drawn in groups E to G, while the rest were grouped in groups A to D. Each club played double round-robin (home and away) against fellow three group members, a total of 6 matches each. Clubs received 3pts for a win, 1pt for a tie, 0pts for a loss. The clubs were ranked according to points and tie breakers were in the following order:
Points earned between the clubs in question
Goal Differential between the clubs in question
Points earned within the group
Goal Differential within the group
Goals For within the group
The seven group winners along with the defending champion advanced to the quarter-finals.
Knockout Round
All eight clubs were randomly matched; however, the only restriction was that the clubs from the same country could not face each other in the quarter-finals. The games were conducted in 2 legs, home and away, and the aggregate score decided the match winner. If the aggregate score couldn't produce a winner, "away goals rule" was used. If still tied, clubs played extra time, where "away goals rule" still applied. If still tied, the game went to penalties.
Participating clubs
After their admission into the AFC, Australia were granted two entries. Because of this, both Thailand and Vietnam were restricted to entering just one club, with a second club from each country playing in the AFC Cup.
Esteghlal were disqualified from the competition by the AFC for failing to submit their player registration form in time. Consequently, Group B was reduced to three teams.
Group stage
The draw took place in Kuala Lumpur on 22 December, allocating teams into seven groups. In February, the AFC disqualified Esteghlal Tehran from Group B for failing to register their players in time.[citation needed]
Group matches were scheduled to be played over match days on 7 March 21 March 11 April 25 April 9 and 23 May 2007.