Arizona (57-48) at Los Angeles (47-57)

Justin Upton(notes) has been the Arizona Diamondbacks’ hottest hitter recently. To keep surging, though, he’ll have to quickly solve his struggles against the Los Angeles Dodgers.

Upton and the Diamondbacks continue their nine-game trip through California on Friday night with the first of three at Chavez Ravine.

The Diamondbacks’ center fielder extended his hitting streak to nine games with a single in Thursday’s 4-3 loss to last-place San Diego. Upton, who had gone deep three times while Arizona won the first two games of the set, is hitting .545 (18 for 33) with five homers and 15 RBIs during his run.

Upton leads the Diamondbacks with a .303 batting average, 20 homers and 61 RBIs. However, he’s 1 for 22 (.045) with seven strikeouts against the Dodgers this season, and 2 for 16 (.125) with six strikeouts lifetime against scheduled starter Ted Lilly(notes).

The Diamondbacks (57-48), who are four games behind NL West-leading San Francisco, will take on the Giants in a three-game set starting Monday. Arizona first will look to generate some momentum before heading to the Bay Area by improving its 4-2 record against the Dodgers.

“I think overall we’re pretty good at (focusing on the) game at hand,” manager Kirk Gibson told the Diamondbacks’ official website. “Overall they’ve had a good attitude. They know what’s going on.”

With the first slump of his major league career behind him, Josh Collmenter(notes) (6-5, 2.74 ERA) will try to win his third straight start for Arizona.

In six starts from June 9 to July 6, the rookie had been 0-4 with a 5.08 ERA while receiving three runs of support. Collmenter has since turned things around while being aided by a resurgent offense.

In home wins over Milwaukee and Colorado, the right-hander surrendered just three runs and nine hits in 15 innings while getting 15 runs of support. Last Saturday, Arizona jumped out to a 5-0 first-inning lead and rolled to a 12-3 win over the Rockies.

“It’s big anytime you have a lead when you’re a pitcher, especially early on,” Collmenter said. “It gives you a little cushion out there, and lets you ease into it and get more comfortable on the mound - knowing you don’t have to be quite as perfect.”

In his only previous start against Los Angeles, Collmenter gave up two hits in six innings as Arizona won 1-0 on May 14.

A lack of run support has plagued Lilly (6-10, 5.08) when facing the Diamondbacks this season. The left-hander has received one run in each of his two losses to Arizona while being tagged for eight runs and nine hits in 12 2-3 innings.

After losing to the Diamondbacks on July 17 in Phoenix, Lilly matched a season high by surrendering six runs in five innings last Saturday, but the Dodgers rallied for a 7-6 walkoff win over Washington.

Lilly is 1-5 with a 7.47 ERA over his last seven outings.

Los Angeles (47-57) had its four-game winning streak halted with a 3-1 loss to Colorado on Wednesday. Rod Barajas’(notes) one-out homer in the ninth inning helped the Dodgers avoid being blanked by the Rockies for the third time in 2011.

Slugger Matt Kemp(notes) hasn’t homered in 10 games since hitting one in a 3-2 loss to Arizona on July 16. Kemp remains second in the NL with 24 homers, three behind St. Louis’ Lance Berkman(notes).