Helmsman Chris Draper made a clutch move right before the start and sailed Italy's Luna Rossa to victory Friday over Artemis Racing and a 3-0 lead in the America's Cup challenger semifinals.
Luna Rossa can wrap up the best-of-seven series Saturday on San Francisco Bay and earn a berth against Emirates Team New Zealand in the Louis Vuitton Cup final.
Unless Artemis can extend the series, its campaign will be finished after only four races. The Swedish-backed syndicate has been scrambling to catch up since May 9, when sailor Andrew "Bart" Simpson was killed in the capsize of its first boat.
Artemis was going through a slow tack during prestart maneuvers when Draper tucked the chrome-hulled Italian catamaran under the Swedish boat and into control. Luna Rossa led at every mark and won by 1 minute, 18 seconds.
It was the closest margin in the challenger series so far.