Yonder Alonso knocked in three runs, including a go-ahead homer, backing Clayton Richard\'s solid start Saturday in San Diego\'s 9-3 win over Arizona. The Padres trailed 2-1 when Carlos Quentin\'s solo shot in the fourth inning forged a tie game. Alonso then put San Diego ahead to stay in the next frame when he smashed a 1-2 pitch from Ian Kennedy (11-11) over the right-field fence for a solo shot. Chase Headley added a bases-empty clout and a sacrifice fly for the Padres, who clinched their three-game series with their sixth straight victory. Richard (11-12) won for the fourth time in five starts, surrendering three runs on seven hits in an eight-inning effort. He walked two and struck out four. Kennedy ended up yielding six runs on four hits, lasting 5 1/3 frames. Justin Upton delivered a two-run, inside-the-park homer for Arizona.