Cueto strong, Greinke struggles again as Giants top D'Backs

San Francisco Giants' Joe Panik, right, celebrates his two-run home run against the Arizona Diamondbacks with Denard Span, left, during the fifth inning of a baseball game Thursday, May 12, 2016, in Phoenix. (AP Photo/Ross D. Franklin)
Ross D. Franklin/AP

PHOENIX (AP) Johnny Cueto pitched seven strong innings for San Francisco, Zack Greinke had another rough outing at home for Arizona and the Giants opened a four-game series with a 4-2 victory over the Diamondbacks on Thursday night.

Joe Panik hit a two-run homer off Greinke, who fell to 1-3 in five home starts. Chris Owings had an RBI triple for Arizona.

Cueto (5-1) allowed two runs and eight hits, striking out nine and walking two in a matchup of two of the highest-priced free agent pitchers last offseason. Cueto signed a six-year, $130 million contract, which was dwarfed by Greinke's six-year, $206.5 million deal.

Greinke (3-3) gave up four runs and eight hits in six innings, raising his ERA to 5.26 in eight starts. Greinke led the majors with a 1.66 ERA last season.