The tall left-hander had not allowed a hit through six innings— and Randy Johnson was already out of the game.

Facing the Big Unit, 6-foot-8 rookie Sean West flirted with a no-hitter in his fourth career start.

West did not allow a hit until the seventh inning, Brett Carroll backed him with his first career homer, and the Marlins beat the San Francisco Giants 4-0 on Monday night.

West (1-1) allowed one baserunner—a leadoff walk to Andres Torres in the third—through the first six innings. Edgar Renteria then lined a single to left on West’s first pitch of the seventh.

“The no-hitter was on my mind the whole time, but I tried not to think about it,” West said. “As soon as you think about it, karma’s gonna take care of that hit.”

The 6-10 Johnson has thrown two no-hitters, including a perfect game, in his stellar career.

“It’s a lot of pressure. You try not to think about it but it’s there. But he has to be happy about the way he pitched,” Johnson said.

West gave up two hits, one walk and struck out six in eight innings. He fell short of throwing his first no-hitter at any level.

“I feel sorry for the kid. He pitched a good game. He just made a mistake and that was it,” Renteria said.

West, a Houston native, missed the entire 2007 season after undergoing shoulder surgery.

“I try to throw a no-hitter every start,” West said. “If a hit comes up, I try to throw a one-hitter. If two hits come up, I try to throw a two-hitter, and so on.”

Johnson (5-5), pitching on short rest, four days after he earned career victory No. 300 at Washington, allowed three runs, seven hits, three walks and struck out five in five innings.

“For the most part, my pitches weren’t as good as (during No. 300) from a location standpoint, but I was pretty much able to pick up the team and get it done coming back early like that,” Johnson said.

Carroll hit a three-run homer in the second to give the Marlins a 3-0 lead. He also singled and tripled for the Marlins, who earned a split of the four-game series. Leo Nunez pitched a scoreless ninth to finish the combined three-hitter, Florida’s first shutout this season.

After Dan Uggla a single and Ronny Paulino walked, Carroll sent Johnson’s 90 mph fastball over the left-field scoreboard.

“I’m speechless, in all honesty,” Carroll said. “I’m humbled by (hitting it off) a guy of that stature.”

San Francisco’s Aaron Rowand went 0-for-4 and had his career-high hitting streak stopped at 17 games. Renteria also singled in the ninth to have two of San Francisco’s three hits.

“It shows you how well the kid (West) was pitching to shut down a hot hitter like Rowand,” Giants manager Bruce Bochy said.

Johnson had been 6-1 with a 2.84 ERA in nine career regular-season starts on short rest before Monday.