LOS ANGELES (AP) Mike Bolsinger learned a few things about pitching with an attitude and succeeding under duress last year during his rookie season with the Arizona Diamondbacks. And now, he appears to have straightened out all of those problems with the Los Angeles Dodgers.
Having a power-hitting lineup with the most home runs in the National League behind him didn't hurt, either.
Andre Ethier and Jimmy Rollins hit three-run shots in support of Bolsinger and Howie Kendrick had three hits in his return to the starting lineup, leading the NL West-leading Dodgers to a 9-3 victory over the Diamondbacks on Monday night.
''In Arizona, it had more to do with me,'' Bolsinger said. ''I went out there with a bad mentality. I'd have a bad start and thought: `If I pitched bad, I'm going to get sent down.' But you can't think like that. It's crazy to see how much I've kind of grown up mentally in just one year. My mentality is so different than it was last year.''
Bolsinger (4-1) allowed two runs and three hits in seven innings, striking out eight and walking two after getting staked to a 9-0 lead. Ender Inciarte's fourth-inning single was the only hit against the right-hander until the sixth, when he gave up a leadoff walk to Nick Ahmed, a one-out infield hit by Inciarte and a two-run double by A.J. Pollock.
Pollock's hit snapped Bolsinger's season-opening string of 24 consecutive scoreless innings at Dodger Stadium.
Rubby De La Rosa (2-3) gave up nine runs and 10 hits over five innings in a matchup of pitchers going up against the teams they originally signed big league contracts with.
De La Rosa joined the Dodgers as a non-drafted free agent in July 2007. Bolsinger was selected by the Diamondbacks in the 15th round of the 2010 draft and went 1-6 with a 5.47 ERA in nine starts as a rookie last season before the Dodgers purchased his contract in November.
Kendrick, starting at second base for the first time in five games due to a left knee strain, opened the scoring in the first with an RBI single. He led off the fourth with another single - one of five consecutive Dodgers to reach base - and they padded their lead to 6-0.
Alex Guerrero and Ethier delivered RBI singles and Rollins drove De La Rosa's 2-1 fastball to center field for his seventh homer, ending a stretch of 79 at-bats in which he had only two RBIs.
''Fortunately, I've been around long enough that I don't panic,'' the 13-year veteran shortstop said. ''And if you don't hit well, just hopefully hit well in situations. Charlie Manuel used to always say in Philadelphia that it's not always about how many hits you get, but the number of hits you get when it counts. Tonight I got only one hit, but it was a big one.''
Ethier made it 9-0 in the fifth with a first-pitch homer, his eighth of the season, after Kendrick singled for the third time and Yasmani Grandal doubled. De La Rosa has surrendered 24 runs, 29 hits and six homers in 21 innings over his last four starts, raising his ERA to 5.84.
''He's one of our guys,'' manager Chip Hale said when asked how much more rope he was going to give De La Rosa. ''We're in a situation here where we're trying to win games - and also trying to develop guys along the way. And with Rubby's stuff and his changeup and his velocity, we feel like he's worth the development. So we're just going to keep working with him and get him better. That's our job.''
Diamondbacks: Had the first overall pick and selected SS Dansby Swanson, who played 2B for Vanderbilt's National Championship team last year and earned Most Outstanding Player honors in the College World Series. This was the first time the D-backs had the No. 1 selection since they took Justin Upton in 2005.
Dodgers: Selected Swanson's Vanderbilt teammate, RHP Walker Buehler, 24th overall. This was the 12th time in the last 13 years that the organization tabbed a pitcher with its first pick, including Clayton Kershaw in 2006 and Chad Billingsley in 2003. The only non-pitcher during that stretch was SS Corey Seager in 2012 (18th overall).
Diamondbacks: Robbie Ray (1-0) is making his third start since his recall from Triple-A Reno. He still has rookie status despite pitching in nine games last season for Detroit - six starts - and allowing 26 earned runs in 28 2-3 innings with a 1-4 record.
Dodgers: Carlos Frias (4-3) held the Diamondbacks to four hits in 5 1-3 scoreless innings on May 1 in an 8-0 victory. In six starts since then, he is 2-3 with a 5.19 ERA.