Diamondbacks 5, Padres 2: Didi Gregorius drilled a tiebreaking three-run homer in the eighth inning to lift host Arizona over San Diego.Alfredo Marte drew a one-out walk and Jake Lamb singled against Kevin Quackenbush (2-3) before Gregorius broke out of a 2-for-39 slump by lining the ball over the right-field fence. Addison Reed worked the ninth for his 30th save.Lamb also hit his first major-league homer earlier in the contest as the Diamondbacks improved to 7-14 in August. The Padres had just three hits while dropping to 2-7 on a 10-game road trip.Diamondbacks starter Vidal Nuno allowed two hits in 7 1/3 innings and left with the bases loaded and a 2-0 lead. San Diego's Yangervis Solarte spoiled Nuno's attempt to win his first game since joining Arizona by bouncing a two-run single to center off Oliver Perez (3-3).Cliff Pennington had a run-scoring single in the first and Lamb went deep in the second as the Diamondbacks took a 2-0 lead. Padres starter Andrew Cashner was activated off the disabled list and gave up two runs and seven hits in five innings.GAME NOTEBOOK: Quackenbush has allowed two homers this season - both coming against Arizona. … Nuno is 0-3 in nine starts with the Diamondbacks since being acquired from the New York Yankees. … Padres 2B Jedd Gyorko (hamstring) wasn't in the starting lineup but struck out as a pinch hitter in the eighth.