SAITAMA, Japan, July 30 (Reuters) - Team USA shut down Japan"s long ball game and improved to 2-0 in the preliminary round of Olympic women"s basketball on Friday. Japan led in the first quarter, boosted by accuracy from the three-point line. But the Americans adjusted defensively and were ahead 86-69 by the final whistle at the Saitama Super Arena, north of Tokyo. "They were always in the game," Team USA coach Dawn Michelle Staley said about Japan. "The gap is closing with us and Japan and the rest of the world." A"Ja Wilson, who plays for the WNBA"s Las Vegas Aces, led in scoring for the U.S. with 20 points. The Americans will face Nigeria on Monday for their last match in the preliminaries. The Belgium women"s team cruised to a second victory in group play with an 87-52 win over Puerto Rico, who slid to 0-2. Belgian sisters Kim and Hanne Mestdagh combined for 33 points. The Belgian Cats beat Australia on Tuesday and will attempt a clean sweep of Group C when they face China on Monday. "China will be a whole different game, very physical, something completely different than what we"ve seen against Australia and today," said Hanne Mestdagh. "We"re going to enjoy the win on the day, recover a little bit, and tomorrow on we"ll fully prepare for China." The match between China and Australia came down to a thriller, with Australia"s Jenna O"Hea tying the game at 74-74 with a three-pointer with two seconds remaining. But as time ran out, China"s Li Yueru drew a foul and converted on two free throws to deliver a 76-74 win for her team. China are now 2-0, while Australia slid to 0-2. The French women"s team bounced back from a loss to Japan to defeat Nigeria 87-62. The French swarmed on offence, with five players accounting for more than 10 points each. "It was necessary after the defeat against Japan to have a good reaction and I"m proud of my team this evening because they did," said coach Valerie Garnier.