Argentine Leonardo Mayer converted on his 11th match point in the fading sunlight in Buenos Aires Sunday night to defeat Brazilian Joao Souza 7-6 (4), 7-6 (5), 5-7, 5-7, 15-13 in the longest singles match in Davis Cup history. The win, contested for six hours and 43 minutes, leveled the best-of-five Davis Cup tie between the South American rivals at 2-2. Darkness forced the opening round competition to be completed Monday, with Argentina’s Federico Delbonis leading Brazil’s Thomaz Bellucci 6-3 in the deciding rubber when play was suspended. Only John Isner and Nicolas Mahut’s 11-hour and 5-minute marathon at Wimbledon in 2010 exceeded today’s match. That epic was contested over three days, however. John McEnroe and Mats Wilander held the previous Davis Cup record of six hours and 22 minutes set in 1982. Mayer hit 16 aces and 89 winners, while overcoming 134 unforced errors. The Argentine won six of 23 break points, Souza seven of 11. Mayer won 244 points, Souza 233. Mayer had three match points at 5-4, two at 9-8, and four at 12-11, all on Souza’s serve. He squandered the 10th in the final game before finally sealing the win. Souza broke for 6-5 and served for the match, but was broken right back. Mayer dropped to the ground after the final point, as the crowd and his teammates celebrated wildly. “We are a team, you have to have faith.” Mayer said afterward, with tears in his eyes.