Azshara and her highborne were prepared for them, and her chaotic magics ripped Malfurion's forces to shreds. But it was the sight of Tyrande falling to the hands of Azshara's former Highborne, now transformed into satyrs that gave Malfurion the strength for one final strike.
Azshara's battle with Malfurion threw the portal out of its magical alignment, and the vortex grew unstable. Malfurion cast a spell to create a gigantic gale that would rip all the demons from the ground and send them on a one-way trip into the Well and to the Twisting Nether.
The Well of Eternity then started to collapse on itself, pulling land, Azshara's palace and the ruined city of Zin-Azshari into itself. Although Sargeras knew that the portal was closing, he tried to do the unthinkable - step into the portal to recreate it and enter Azeroth. The portal finally collapsed and trapped Sargeras in it. The Well of Eternity exploded in a catastrophic eruption that left the world sundered forever.
However, Malfurion survived. Constructing crude rafts and sailing to what would become Kalimdor, Malfurion, Tyrande, and Cenarius agreed to lead their people to a new home.