Novak Djokovic clinched his third U.S. Open and 14th major crown Sunday night, tying Pete Sampras’s record. The three-hour match was witnessed by a crowd of more than 23,000 -- including billionaires from Wall Street and Silicon Valley. The Serb’s straight-sets victory over Argentina’s Juan Martin del Potro was played on Arthur Ashe Stadium under a closed roof in front of fans who ventured out to Flushing Meadows in rain and temperatures that were more than 30 degrees cooler than those that plagued players for most of the tournament.