LONDON—Great for most of the Olympics, then just good enough for gold.The U.S. men’s basketball team defended its title by fighting off another huge challenge from Spain, pulling away in the final minutes for a 107-100 victory Sunday that gave the Americans their second straight gold medal.And just like 2008, they had to work for this one.LeBron James capped off one of basketball’s most brilliant individual years with a monster dunk and a huge 3-pointer in the final 2:50, helping the Americans win the competitive game that few would have seen coming after they had been so dominant for so long in London.Yet four years after beating Spain 118-107 in a classic in Beijing, the Americans found themselves in another tight one, unable to ever really slow the Spanish down until the closing minutes.Kevin Durant scored 30 points and James had 19 on a day he joined Michael Jordan as the only players to win the NBA title, regular-season MVP, NBA Finals MVP and Olympic gold.Coach Mike Krzyzewski, who has said he’s retiring as national team coach after restoring the Americans to their place atop world basketball, emptied his bench in the final minute.James stood with both arms in the air, then held Durant in a long hug before they both headed to the bench.The Americans, who insisted they were better than their 2008 version and even good enough to take a game from the 1992 Dream Team, may not have been at that level.But they were better again than Spain — though not by much.The Americans hugged at midcourt, and then after being handed flags, this group of NBA players — and one kid just out of college — who grew into a tight-knit group during their time together, paraded around the floor, the Stars and Stripes flowing off their backs like capes. Then they were Olympic super heroes again, but they had to fight until the finish.Kobe Bryant, now with a second gold medal to go with his five NBA championships, added 17 points for the Americans.Pau Gasol scored 24 points and Juan Carlos Navarro had 21 for Spain.