BOSTON — Rick Porcello had a simple answer to why he can’t think about his current success.

He knows there are a lot more important things he’s helping the Boston Red Sox chase.

Porcello became the majors’ first 18-game winner and the first Red Sox pitcher in 70 years to open a season 13-0 in Fenway Park, going seven solid innings in Boston’s 9-4 victory over the Tampa Bay Rays on Monday night.

“When you look at the standings we’re still chasing so there’s nothing to be complacent about. You still have to gain ground on Toronto. We’re not in first place right now,” the right-hander said. “That’s how I kind of view it. I don’t look at it as a personal level: ‘I’m doing well so I can relax.’ We’re still fighting so we can get where we have to be.”

Mookie Betts hit his 30th homer, a solo shot, and drove in two runs for the Red Sox, who hold the AL’s first wild-card spot but had lost four of five.

Brock Holt had three hits and drove in two runs, Travis Shaw had three hits and Chris Young added a tiebreaking two-run double for Boston.

The Rays, buried in last in the AL East, have lost three of four.

Porcello (18-3) allowed three runs and six hits, striking out seven without issuing a walk to become the first Boston pitcher since Dave “Boo” Ferriss finished 13-0 at home in 1946 to start a season by winning his initial 13 decisions in Fenway.

“Rick has been a model of consistency,” Red Sox manager John Farrell said.

Red Sox 2B Dustin Pedroia missed the game after a death in the family, but he’s expected back Tuesday.

Matt Andriese (6-6) took the loss, giving up a season-high seven runs in four-plus innings. Evan Longoria had two sacrifice flies for the Rays, who split a four-game series against the Red Sox at home last week.

“I just wasn’t at my best, so it’s kind of what happens when you leave some elevated pitches up there,” Andriese said of facing the majors’ top scoring team. “It’s a good hitting lineup and they made me pay.”

The game was tied 2-2 after three innings before Boston took charge with three runs in the fourth and two in the fifth.

“Really impressed with the offense that they came right back and got two quick runs to tie it back up,” Rays manager Kevin Cash said. “But after that Porcello seemed to kick it in gear and they kind of had Matt’s number a little bit.”

Young lined his two-run double past third baseman Longoria, moving the Red Sox ahead 4-2. Longoria seemed to mistime the speed of the liner, raising his glove a bit late. Holt added an RBI double.

After the Rays cut it to 5-3, Betts lined a run-scoring double into the left-field corner. He scored on Shaw’s infield hit.

Betts homered over the Green Monster, hitting a billboard with the ball bouncing onto the field.

TRAINER’S ROOM

Rays: Cash has decided to go with six starters when RHP Aex Cobb returns to the rotation this weekend against Toronto after being sidelined since Tommy John surgery in May 2015. “We have six guys, all with the reason to be starters,” Cash said.

Red Sox: Farrell said RHP Koji Uehara (strained chest muscle) had another strong bullpen session. The next steps are for him to have bullpen on Wednesday before facing live hitters Saturday. .Farrell also said C Ryan Hanigan (left ankle tendinitis) is expected to come off a rehab assignment and join the team when they start a road trip in Oakland on Friday.

MAGICIAL MOOKIE

The 23-year-old Betts joined Ted Williams (1939, 1941) and Tony Conigliaro (1965) as the only Red Sox with 30 homers in a season before turning 24.

“It feels pretty good. It affected the game. That’s what I set out to do,” he said. “It’s pretty cool hitting 30.”

UP NEXT

Rays: RHP Jake Odorizzi (9-5, 3.53 ERA) is set to start Tuesday. He pitched seven innings at home against the Red Sox last Thursday, his longest outing in a month.

Red Sox: LHP Drew Pomeranz (2-3, 4.06) is looking to build on his strong start last Thursday against the Rays when he struck out a career-best 11, but got the loss despite giving up only two runs in six innings.