Sir Ben Ainslie's British team won one and lost one of their opening two races as the Louis Vuitton America's Cup Qualifiers got under way on Saturday.
After Friday's opening day in Bermuda was postponed due to strong winds, Ainslie's Land Rover BAR team defeated Sweden's Artemis Racing in their opening race.
But they were then defeated by SoftBank Team Japan after helmsman Ainslie was penalised for a start-line collision.
BAR, whose crew also includes tactician Giles Scott, who won Olympic gold in Rio last summer, still finished the day top of the table with defending champions Oracle Team USA, whom the top challenger will meet in the 35th America's Cup starting on June 17.
Oracle won both of their races on Saturday, but the two teams are level on three points, Ainslie's team having carried two points into the regatta thanks to winning the America's Cup World Series. The Americans started with one point.
Artemis, Emirates Team New Zealand and SofaBank all have one point.
