Yankees pitcher Shane Greene delivers a pitch vs. the Orioles during the fifth inning Saturday. Greene tossed seven-plus scoreless innings to help New York down Baltimore. (Nick Wass/AP)

Fans in navy were at least five rows deep along the third base dugout before the game, hoping for an autograph or a ball to be thrown their way by one of their favorite stars. Most wore Derek Jeter’s number on their back, and some had Mark Teixeira’s jersey, applause for both rivaling any for the Baltimore Orioles.

But the star for the Yankees on Saturday afternoon wasn’t Jeter, Teixeira or any of the team’s other marquee names. Instead, it was rookie right-hander Shane Greene, making just his second major league start, who threw 71 / 3 scoreless innings at the first-place Orioles, sparking the Yankees to a 3-0 win.

The unknown player is what Orioles Manager Buck Showalter said creates anxiety and presents a challenge to advance scouts. Though Baltimore’s Class AAA team had faced Greene, he had never pitched against the Orioles (51-42).

“You can watch every pitch they’ve thrown, but there’s no substitute for getting in there in the box off of them,” Showalter said. “Whether it’s a 4 o’clock start, a 7 o’clock start or a 1 o’clock start, you’re going to have success if you do what he did today.”

The 25-year-old Greene, the Yankees’ minor league player of the year last season, used a repertoire that includes a slider, fastball and curveball to strike out nine. In his debut Monday, Greene held the Indians to two runs in six innings. Greene went deeper Saturday, yielding just four hits and two walks.

“It didn’t look like it” was his second start, right fielder Nick Markakis said. “Nothing was straight.”

The Orioles threatened in the fifth when Manny Machado’s grounder found a hole in the left side for their first hit. Ryan Flaherty’s single to center put runners at the corners with two outs. Just when it seemed like the rookie was unspooling, he got Nick Hundley to strike out swinging on a 95-mph fastball.

Yankees catcher Francisco Cervelli leaped up and gave a fist bump in the direction of Greene. Greene then also allowed himself a more reserved one, otherwise stoic during his outing.

The Orioles started the bottom of the sixth with back-to-back hits off Greene, putting Steve Pearce and Markakis at first and second. Just when it again seemed the Orioles had solved the right-hander, he forced Adam Jones into a double play. Greene then struck out all-star Nelson Cruz for the third time to get out of the inning.

“He had a really good slider and a good two-seamer,” said Orioles starter Chris Tillman. “He did his job, and you have to give credit to him.”

Tillman gave up an early run in the third when Teixeria’s double brought Brett Gardner home. He flirted with danger throughout his start, surrendering seven hits and putting runners on before having to pitch out of the jam. It caught up with him in the seventh.

A grounder to left from Jeter pushed Kelly Johnson across for a 2-0 lead. Orioles reliever T.J. McFarland replaced Tillman with two outs, but Jacoby Ellsbury promptly hit a liner to right field to score Jeter.

The insurance was nice, but unnecessary for Greene. On a pitching staff that has been ravaged by injuries — four-fifths of the opening day rotation is out until at least August — the fresh-faced Greene won’t be unknown for long. Walking back to the dugout after his final out, the fans in navy at Camden Yards stood to applaud him.