VANCOUVER, British Columbia — Giles Barnes scored twice and the Vancouver Whitecaps beat the Portland Timbers 4-1 on Sunday to eliminate the defending MLS Cup champions from the playoffs. Both of Barnes’ goals came in the first half at BC Place and the Timbers couldn’t catch up. The Whitecaps (10-15-9) had already been eliminated from the playoffs but they claimed the Pacific Northwest’s Cascadia Cup on goal differential with the victory. Portland (12-14-8) finished the season without a win on the road. Barnes’ first goal came in the 13th minute, and he slotted his second in the 32nd.