Danny Espinoza smashed a go-ahead, three-run homer to highlight an eighth-inning rally Saturday that carried Washington to a 10-7 victory over Miami. Trailing 6-4 in the eighth, the Nationals erupted for four runs -- all unearned -- to grab control of the contest. The floodgates were opened when Marlins reliever Mike Dunn (0-1) dropped a routine throw while covering first base on Adam LaRoche\'s infield grounder. Jayson Werth walked and one out later Steve Lombardozzi plated LaRoche with a single, cutting the Nats\' deficit to one run. Pinch-hitter Tyler Moore came up and delivered a game-tying single and Espinoza then followed with his decisive three-run blast into the left-field bullpen. Bryce Harper made it back-to-back homers with a solo shot to cap the big rally for National League East-leading Washington, which lengthened its lead over second-place Atlanta to three games with the comeback win. Ryan Mattheus (4-1) earned the victory with 1 2/3 scoreless relief innings. Carlos Lee and Donovan Solano each drove in a pair of runs and Jose Reyes went 3-for-4 with four runs scored for Miami.