BALTIMORE -- After an historically bad May, the Giants’ starters were probably eager to flip the calendar to June.

Rookie Shaun Anderson made sure the club’s rotation opened the month on the right foot, firing seven strong innings in the best start of his nascent career to help propel the Giants to an 8-2 win over the Orioles on Saturday afternoon at Oriole Park.

Anderson allowed two runs on five hits and threw a career-high 105 pitches to earn his first win in his fourth start -- and his first on the road -- for the Giants. The 24-year-old right-hander walked one and struck out four, lowering his ERA to 4.09.

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Brandon Belt drove in a season-high four runs and Buster Posey crushed his third home run of the season to help back Anderson, who snapped the Giants’ streak of 40 consecutive games without a seven-inning outing from a starter, the longest stretch in MLB this year and the longest streak by the Giants in the last 100 years, according to Stats, LLC. He became the first Giants starter to complete seven innings since Madison Bumgarner on April 13.

“Strong kid,” manager Bruce Bochy said. “He maintained his stuff. He was still hitting 94 [mph] up there in that last inning. He had good stuff. Good movement on the fastball. Good slider. He just pitched well. It was good to see that. We haven’t had a lot of those, to be honest. The ’pen could have used a big break today, and he allowed us to do that. He just did a terrific job.”

Anderson’s quality start came two days after fellow rookie Tyler Beede delivered six innings of one-run ball against the Marlins, an encouraging sign for the Giants, who are increasingly looking toward the future after their 23-34 start to the season.

Those performances have helped stoke optimism that the Giants’ rotation can turn it around after logging an ugly 7.32 ERA in May, the highest for the club in any single month since it moved to San Francisco in 1958. It also marked the highest monthly ERA by a team’s starting staff since the A’s rotation posted an 8.25 ERA in September 2015.

Anderson wasn’t immune to those struggles, yielding six runs (four earned) over five innings against the D-backs in his previous start on Sunday.

After the rough showing, Anderson sat down with pitching coaches Curt Young and Matt Herges and catcher Posey to work on refining his location. (Posey, who homered in the third inning as the designated hitter, left the game after developing right hamstring soreness in the seventh. Bochy said Posey is considered day to day.)

“I had a couple [of] missed locations last outing,” Anderson said. “We broke it down and talked about why they were missed, and why the result was how it was. Going into this game, I just knew I had to locate.”

Anderson looked sharp from the outset against the Orioles, retiring the first six batters he faced. He opened his start with three scoreless innings before Renato Nunez drove a first-pitch fastball over the left-field fence to put Baltimore on the board in the fourth. The Orioles scored their only other run off Anderson in the fifth after Stevie Wilkerson drew a leadoff walk and scored on Austin Wynns’ two-out RBI single.

Anderson had never thrown more than 102 pitches in his professional career, but Bochy chose to send him out for the seventh with his pitch count at 84. He subsequently found himself locked in an 11-pitch battle against Wilkerson, who fouled off six pitches before striking out swinging on a 92-mph fastball.

“I knew my pitch count was going up, and I knew I wanted to get through that seventh,” Anderson said. “He was taking me away from that. I knew I had to bear down and make sure I made pitches. I located that last fastball, and he swung through it.”

Anderson then struck out Rio Ruiz swinging on another fastball and coaxed a groundout from Hanser Alberto to cap his outing.

“I thought he had a good look about him in that seventh inning,” Bochy said. “He wasn’t looking for help. I do think he has an edge to him. You can tell, he’s a really good competitor.”