Alex Lange is back.

You know, the stud freshman pitcher who mowed through opposing batting orders during his first two months of the season, the star rookie who wowed LSU fans and stunned the college baseball nation, the hard-throwing, heady 19-year-old who seemed invincible until an elbow issue?

He returned Saturday night against his home-state team, tearing through Missouri’s order in LSU’s 8-2 series-clinching win at Alex Box Stadium.

Lange struck out eight and allowed just four base runners in a splendid seven-inning stay, and Chris Chinea drove in three runs — two of them on his team-tying eighth home run of the season.

“Wow. What a performance by Lange tonight,” coach Paul Mainieri said. “That was obviously the highlight. Everybody had been predicting his demise, that the kid was going into the tank because he wasn’t striking out 10 batters every game.

“I told you, ‘Be patient with this kid. He’s just a true freshman,’ ” Mainieri continued. “I thought tonight the ball came out of his hand great.”

The No. 1 Tigers (42-8, 18-7 Southeastern Conference) claimed a sixth straight SEC series, maintained their position atop the league standings and locked up an eighth SEC series in their first nine. Just two other Mainieri-coached LSU teams have done the latter — the College World Series squads of 2009 and 2013.

LSU is streaking at just the right time, with just five games left in the regular season.

The Tigers likely have secured a top-eight NCAA national seed, have won 19 of the past 22 games and are a game ahead of Texas A&M and Vanderbilt in the league standings.

And they have almost a completely fresh bullpen for Sunday’s 2 p.m. series finale.

Senior left-hander Kyle Bouman (1-1) will start Sunday’s series finale.

Mainieri isn’t thinking about a sweep. He’s thinking about keeping pace in a dual championship race for the SEC West and overall SEC regular-season crowns.

“If my calculations are correct,” Mainieri said, “our magic number is three with Texas A&M and three with Vanderbilt.”

Mainieri and pitching coach Alan Dunn saw something Friday they haven’t seen in several weeks: Lange shut down an opposing lineup for the first time since suffering elbow tightness last month.

The Missouri native — he grew up two hours from the MU campus — allowed just two hits and one run, a solo homer. Missouri (28-23, 14-12) never got more than one base runner in an inning against him, and Lange faced the minimum in the first, third, fifth and sixth innings.

“Confidence has been there. Stuff has been there,” Lange said. “I’m just putting it all together. Today was a big day for me.”

Lange’s fastball hovered 91-93 mph, and his curveball fooled hitters throughout the night. He saved his best stuff for last, too.

Lange, now 9-0 in his freshman season, struck out four of his last six batters. His eight Ks were the most in a game since March 28 against Kentucky — a four-start span that began with him feeling some “elbow tightness” in an April 3 game at Alabama.

He had a 16-to-15 strikeout-to-walk ratio over that stretch of four starts. He walked just two Saturday in a sparkling performance that likely had many breathing a deep sigh of relief.

“Some of those teams he pitched against were very tough teams to strikeout if you look statistically,” Mainieri said. “It didn’t surprise me he didn’t get a lot of strikeouts in those games. He was much more crisp tonight. I wouldn’t say relieved is the right word. I was happy to see his stuff was a little sharper tonight than it had been.”

Why? Lange said it was his command. He found a groove with his mid-80s curveball by the third inning.

Maybe it had something to do with the opponent, too. Lange is from Lee’s Summit, Missouri, just outside of Kansas City.

“It’s always nice getting that win against Missouri as well,” Lange said with a smile afterward.

Chinea crushed his two-run homer in the fourth inning over the left-field wall — it had an exit speed of 107 mph — and the junior knocked a run-scoring double to the right field corner.

Chinea now has eight home runs in the past 24 games after having none in the first 26.

“He’s going off,” reliever Hunter Newman said. “It’s crazy.”

Shortstop Alex Bregman continued a sizzling streak of his own. He’s got a 15-game hitting streak. Chris Sciambra blistered a pitch in the second inning for an RBI stand-up triple as the Tigers for a second straight night battered one of Missouri’s starting pitchers early on.

They made freshman starter Tanner Houck work. He threw a whopping 64 pitches through the first three innings. He lasted six innings, giving up six hits and four earned runs. The Tigers battered MU’s bullpen, rolling up three runs in the seventh and leading to a backup-filled ninth inning. Mainieri subbed five starters.

Newman pitched a four-hitter over the final two frames, helping save LSU’s bullpen. The Tigers have all but one or two relievers available and haven’t used Zac Person, Jesse Stallings and Parker Bugg.

LSU mixed in some defensive gems behind Lange, and Danny Zardon played error-free at second base in replacement of the ineligible Jared Foster for a second straight game.

Zardon turned his first double play since taking over at the spot — a 6-4-3 smooth turn to negate a leadoff walk in the fifth inning. He also made a charging grab and threw to first in time on a tough play.

Third baseman Conner Hale caught a pop fly while leaning over the Missouri dugout to leadoff the third. He hung over the dugout railing to snatch the ball, eliciting a loud roar from more than 8,000 at the Box.

They applauded the loudest for Lange, of course. They welcomed the old Alex back to Alex Box.

“I enjoyed it,” Lange said. “This place was going nuts.”

Follow Ross Dellenger on Twitter: @DellengerAdv.