(Sports Network) - The top two teams in the National League West start up an important three-game series this evening at Chase Field, where the first-place Arizona Diamondbacks host the Los Angeles Dodgers in a battle of struggling clubs.

Arizona comes in owning a 3 1/2-game lead on the Dodgers despite having lost its last four contests. That's because Los Angeles has yet to win any of the first seven tilts of its current 10-game road trip.

The Dodgers' three most recent defeats came at the hands of the lowly Washington Nationals, capped by an 11-2 shellacking in Thursday's series finale.

Los Angeles rookie Clayton Kershaw (2-5) lasted just 2 1/3 innings and was roughed up for five runs on five hits, including a pair of homers. Manny Ramirez belted a two-run homer for the Dodgers, but the team managed just five hits overall on the evening.

The Dodgers have now dropped nine in a row on the road, the franchise's longest losing streak as the visitor since an 11-game slide during the 1991 season. For the year, Los Angeles is a subpar 26-39 away from home.

Arizona comes limping back home after being swept in three games by last-place San Diego at Petco Park. The Diamondbacks blew a late four-run advantage in Wednesday's finale, with the Padres erupting for five runs over their final two at-bats to rally for a 5-4 decision.

Chad Qualls (2-8) failed to hold a one-run lead in the eighth, surrendering a pair of runs on three hits in his one inning of work.

D-Backs starter Randy Johnson took a shutout into the seventh inning before allowing three runs during the frame, two of which came via a home run by the Padres' Nick Hundley.

Johnson contributed two hits, including a run-scoring single at the plate. Chris Young also had a pair of hits and an RBI for Arizona, which begins a six-game homestand tonight. The Diamondbacks are 37-28 at Chase Field this season.

Arizona will hand the ball to Doug Davis in tonight's opener as the veteran attempts to build off two straight solid starts. The left-hander matched a season-best with eight strikeouts over seven innings against Florida this past Sunday, but was touched for three runs to receive a tough-luck loss.

Prior to that outing, Davis tossed six innings of two-run ball to defeat San Diego at home on August 19.

The 33-year-old is 1-1 in three 2008 starts against the Dodgers, but has recorded an ugly 9.28 earned run average over those meetings. In his last encounter with Los Angeles, Davis was tagged for five runs and six hits in just 1 2/3 innings during a loss at Dodger Stadium on August 3.

In eight career starts against Los Angeles, Davis is 4-3 with a 2.98 ERA.

Hiroki Kuroda gets the call for the Dodgers tonight and hopes to continue his strong performances during August. In five starts this month, the Japanese import is 2-1 with a 2.10 ERA and has yielded just one run four times over that excellent stretch.

Kuroda was sharp again Sunday in Philadelphia, limiting the Phillies to one run and just two hits in a six-inning no-decision. The 33-year-old also pitched very well against the Diamondbacks on August 2, allowing one run and four hits through 7 1/3 frames in a 4-2 victory at Dodger Stadium.

However, the first-year major leaguer was pounded for six runs (5 earned) and eight hits by the Diamondbacks in only two innings of a July 18 start at Chase Field. Kuroda is 1-1 with a 4.80 in his three matchups with Arizona this season.

The Diamondbacks are 7-5 against Los Angeles in 2008 and have taken four of the six tilts between the clubs in Phoenix this season.