The Opes Prime collapse has allowed iron ore miner Portman to snatch a 10 per cent stake in Golden West Resources from the explorer's hostile suitor, Fairstar Resources, effectively torpedoing Fairstar's takeover bid.

Portman revealed on Friday it had paid $9.4 million or 86¢ a share for 11 million Golden West shares, just half an hour after Fairstar confirmed that 10 million of its shares in Golden West were pledged to Opes Prime creditor ANZ Nominees.