The Washington Wizards had to watch a major piece of their foundation go down in order to get a reminder that the initial building block of the franchise’s rebuilding efforts can still deliver when it counts. John Wall has taken his lumps in recent weeks, deflected criticism and battled through a slump that had him pouting and doubting. Wall even invited his mother, Frances Pulley, up from Raleigh, N.C. last week to provide some home-cooked meals — including his favorite shrimp — and encouraging words. All were needed on Sunday night, as the Wizards let an eight-point lead evaporate into a three-point deficit and then lost Bradley Beal to an ankle injury before Wall scored the game’s final six points — two huge jumpers and two huge free throws — and recorded a game-saving blocked shot to secure a 90-87 victory at Verizon Center. “I like the ball at the end of the games,” Wall said after scoring a team-high 16 points with six assists and five rebounds. “With those type of plays, you want to be the hero. You want to have the pressure. Sometimes you’re going to succeed. Sometimes you’re going to fail, but as long as you have confidence and believe in yourself, you’ll be all right.” Beal had 14 points before going down and had to watch the rest of the game in the training room. He said the X-rays didn’t reveal any serious damage, but was moving throughout the locker room on crutches after the game. He will be evaluated further on Monday.