Auckland City remain a chance of winning a third straight O-League title after sneaking through to the semifinals alongside Waitakere United.
The defending champions needed only a point from a testing trip to Tahiti to face AS Dragon, and a point was all they managed.
Manel Exposito's first-half goal levelled the scores at one and Auckland's defence hung on for dear life to ensure the Spaniard's strike was enough to earn a place in the final four.
They will now face Fijian champions Ba, who finished unbeaten in group A, in a home-and-away semifinal tie, while Waitakere were rewarded for topping group B with a two-legged tie against Vanuatu side Amicale.
Auckland's hopes of winning through to a third consecutive Club World Cup were left hanging by a thread after being beaten by Waitakere in the Super City derby last weekend. But after Dragon were held at home by the lowly Mont Dore during the week, the champions' task was made a little easier.