The Giants' Madison Bumgarner is off to a strong start but routinely struggles against the Diamondbacks.While Kennedy will try for a sixth straight win over San Francisco, Bumgarner will seek to stay unbeaten and end his recent woes against visiting Arizona in Wednesday's series finale.Since winning in the Diamondbacks' season opener, Kennedy (1-2, 5.47 ERA) has gone 0-2 with a 6.62 ERA in three starts. He put together a decent outing Friday in Colorado, allowing three runs and three hits over six innings, but didn't get much help in a 3-1 defeat."He was fine," manager Kirk Gibson said. "We didn't give him any run support."The right-hander would appear to have a good chance to get back in the win column considering he's 5-0 with a 2.21 ERA in eight starts against the Giants (13-8) since 2011. It's his best ERA against any team he has faced more than three times in that span.Bumgarner (3-0, 2.05) had a 6.61 ERA in losing his three starts to Arizona last season, and his 5.59 ERA versus the Diamondbacks since 2011 is his worst against any team he has faced more than once.The left-hander, though, hasn't allowed more than two runs in any of four outings this season. He struck out a season-high 10 in Friday's 3-2 walkoff win over San Diego."He left a couple of pitches up in the first inning but he pitched great," manager Bruce Bochy said. "You can't say enough about the job he did. Bum did a terrific job. He had great stuff."The Giants are hoping Bumgarner can help them bounce back after they blew a chance to complete another comeback win. Buster Posey and Brandon Belt drove in a combined three runs in the final two innings in Monday's series opener, a 5-4 victory, and Belt hit a tying two-run homer in the ninth on Tuesday.Arizona, though, took advantage of an error and a wild pitch in the 11th en route to a 6-4 victory that snapped the Giants' seven-game home win streak and a string of four straight overall victories.Paul Goldschmidt helped the Diamondbacks (11-9) end those runs with a homer and a season-high three RBIs. He was 2 for 12 with one RBI in his previous four games."We made some good plays when we had to and they made a couple mistakes and we capitalized on that," Gibson said. "We played a clean game, made good plays. We've been good at that all year."Gerardo Parra, who had an RBI double in the 11th on Tuesday, is 0 for 10 with five strikeouts all-time against Bumgarner.Belt is 2 for 13 (.154) with eight strikeouts against Kennedy while Marco Scutaro (4 for 10) and Posey (8 for 23) have been a little more successful.