Home runs by Joe Mauer, Justin Morneau and J.J. Hardy enabled Nick Blackburn to leave the game with the lead.

Jon Rauch made it stand up.

Rauch made his season debut for the Minnesota Twins with a perfect ninth inning to earn his first AL save, securing Blackburn’s 5-3 victory over Joe Saunders and the Los Angeles Angels on Tuesday night.

Rauch, an imposing 6-foot-11 right-hander, was assigned the closer’s role last Friday by manager Ron Gardenhire after All-Star Joe Nathan had season-ending Tommy John surgery in March.

“It’s always nerve-racking when you’re trying to replace a guy like Nathan,” Rauch said. “Closing is just three outs later in the ballgame to me, so I don’t need to put any more pressure on myself than need be right now. I was just thinking about going out there, getting it over with and getting the three outs to get us that win.”

Rauch had a career-high 17 saves in 2008 for Washington. But he will have a tough void to fill: Nathan averaged 41 saves over the previous six seasons and finished second in the majors last year with 47 — one fewer than the Angels’ Brian Fuentes.

“It helps,” Rauch said of his limited experience closing with the lowly Nationals. “But back then, I wasn’t on a team that’s expected to win the division and go to the postseason. It’s apples and oranges. Yeah, it was a closing situation, but I can’t rely much on that. I’ve got to take my successes out of pitching in games that mean something. I’m relying more on the times I screwed up in Arizona, when they were on a playoff run, and learning from that.”

Blackburn (1-0) returned to the site of his first big league start and allowed three runs and eight hits over 6 2-3 innings with four walks and four strikeouts. He threw 103 pitches, 69 for strikes.

“I felt fine,” said Blackburn, who led the Twins in innings pitched the past two season. “I hadn’t thrown that much in the spring, but everything felt good and I still felt effective the last inning I went out there.”

Saunders (0-1) gave up five runs and nine hits over five innings and struck out four. The left-hander, who went 7-0 in his final eight regular-season starts last year, surrendered three or more homers in a game for the sixth time in his career.

“The problem was that I was working behind in the count all night from the first pitch on. And in this league, you can’t do that,” Saunders said. “When they know a fastball’s coming, they’re going to hit it hard. And that’s what happened tonight.”

Mauer, who hit a career-high 26 home runs last season en route to his third AL batting title, cleared the center field fence on a 1-1 pitch after Denard Span drew a leadoff walk and was erased on an attempted sacrifice by Orlando Hudson.

“Humble pie Joe, man. He’s as good as they get, and you’d never know it because he’s so humble,” teammate Nick Punto said. “But there’s a lot of things in this game that he wants to achieve that he hasn’t — not that he’d ever tell you those things because he’s so quiet about it.

Mauer was the first player to lead the league in batting average (.365), on-base percentage (.444) and slugging percentage (.587) since George Brett in 1980 — despite missing all of last April with an injury. The twins rewarded the reigning AL MVP and three-time All-Star catcher on March 21 with an eight-year, $184 million contract extension.

“It was nice to see somebody else land a player of that caliber, other than New York, Boston or L.A., and it’s good for baseball,” Punto said.

Morneau led off the third with a towering drive to right field to make it 4-0. The Angels got on the board in the bottom half with Torii Hunter’s RBI single, but Hardy — obtained from Milwaukee for outfielder Carlos Gomez in November — got that run back in the fourth with a drive into the newly installed magnolia trees behind the center field fence.

“Just watching these guys in the spring, you knew we were going to have some runs behind us,” Blackburn said. “This lineup, all the way through, is going to have power. It always helps all pitchers when stuff like that’s going on behind you.”

Hunter hit a two-run homer in the bottom of the fifth to bring the Angels to 5-3 and added a double that chased Blackburn.

The crowd of 43,510 set a Guinness Book record for “the largest gathering of people wearing fleece blankets of one color in one place.

The red “blankies” were inscribed with Hideki Matsui’s name and uniform No. 55. A Guinness World Records adjudicator was on hand to officially certify the new record, which shattered the previous mark of 17,758 fans that was just set on March 5 by the NBA’s Cleveland Cavaliers.