Padres 2, Diamondbacks 1: Cory Spangenberg belted his first career homer with one out in the ninth inning as San Diego recorded its 16th win in its last 19 home games.Pinch-hitting for Cameron Maybin, the 23-year-old Spangenberg deposited a first-pitch sinker from Brad Ziegler (5-3) over the wall in right field. Spangenberg, a first-round pick in the 2011 amateur draft, made his major-league debut in the Padres' 3-1 victory on Monday.Alexi Amarista had an RBI single to plate Rene Rivera in the fifth inning for San Diego, which has improved to a major league-best 21-6 at home since June 29. Kevin Quackenbush (3-3) picked up the win after a scoreless ninth inning while rookie Odrisamer Despaigne settled for a no-decision despite allowing one run on four hits in seven frames.Miguel Montero had an RBI single in the fourth inning and David Peralta had two hits for the Diamondbacks, who have dropped six of their last eight overall and eight straight on the road. Wade Miley saw his winless drought span six outings as he settled for a no-decision despite yielding one run on seven hits in as many innings.The Padres were poised to snap a 1-1 deadlock after Yangervis Solarte and Abraham Almonte singled to lead off the eighth inning. Evan Marshall, however, promptly struck out the next three batters to end the threat.GAME NOTEBOOK: Arizona OF A.J. Pollock was activated from the disabled list after missing three months with a fractured right hand and went 0-for-4. ... Rivera went 2-for-4 to improve to 9-for-20 with three extra-base hits and three RBIs on the homestand. ... Montero went 1-for-3 to improve to 17-for-48 with 12 RBIs against San Diego this season.