Australia II reaffirmed her light-air superiority over Victory '83 today, and in the process all but sewed up the right to challenge for the America's Cup.

The white Australian 12-meter with the winged keel defeated the blue British boat by 2 minutes 20 seconds over the full 24.3-mile America's Cup course. The victory gave her a 3-1 lead in the best-of-seven final challenger series and put her in position to wrap up the series Monday.

Australia turned a nearly dead-even start into a 1-minute-10-second lead by the first mark, 4 1/2 miles upwind. It was typical of her performance this year, as she continually has managed to outpace the British boat upwind in light airs.

The British conceded that, spokesman Jim Alabaster saying, "There is a definite pattern" of Australia II managing to surge a minute or more ahead in each upwind leg as long as the winds don't exceed 10 knots.

Alabaster said the British will be banking on stronger breezes Monday to stay in the running. The forecast calls for 15 knots or better, and Australian skipper John Bertrand said he welcomed a change from the pattern that has plagued this America's Cup summer.