NEW YORK -- A year ago, Luis Severino was concluding a disappointing season filled with frustrating results. Instead of letting the negativity linger from a poor season, Severino went to work on things to get better.

This year, the Yankees are constantly seeing the results pay off as the games increase in significance.

Severino turned in another outstanding outing Friday night when he tied a career high by pitching eight innings as the New York Yankees beat the Baltimore Orioles 8-2.

"I think whether it's a guy that you've seen do this before it or not, it's just been impressive what he's done, the way he's pitched all year long for us," Yankees manager Joe Girardi said. "We really believed that he was always a starter. Larry (pitching coach Larry Rothschild) had a huge belief in his heart and did some things the last couple of weeks in spring training and Sevvy's been a different guy, the guy that we thought he could be and he's just continued to get better and better."

Severino (13-6) was 0-8 as a starting pitcher last season when he injured his triceps and was demoted to the minors. He pitched well in relief but still questions persisted about his role and whether he would make the rotation in spring training.

"I give him a lot of credit," Girardi said. "He went to work and he's been outstanding."

"That's why I went over to work to show the Yankees and the fans that I can be a starting pitcher," Severino said.

Now the questions are where Severino might pitch in any possible postseason games should the Yankees get there. Severino continued to enhance New York's postseason chances by shaking off a two-run homer to Welington Castillo in the third and allowing three hits while completing eight innings for the third time this season. He also pitched eight innings April 18 vs. the Chicago White Sox and May 24 vs. the Tampa Bay Rays.

He also struck out seven, raising his season total to 218, tying him with Melido Perez for fifth place on the team's all-time list. He is 30 shy of Ron Guidry's record set during the left-hander's 25-3 1978 season.

The right-hander won for the eighth time in his last 11 starts. He retired 19 of the final 21 hitters after Castillo homered and is holding opposing hitters to an .083 average (6-for-72) in his last three outings.

"He's tough, he's got plus fastball and plus slider," Castillo said. "So you just got to go out there and wait for one pitch and not try to miss it because he don't make many mistakes."

Severino's ace-like showing helped the Yankees (81-66) tie a season high by getting to 15 games over .500. They also got their 11th win in 15 games since getting swept in a three-game series by the Cleveland Indians on Aug. 28-30.

"I'm excited," Severino said. "We're playing good. We're hitting good. I'd be honored (to start the playoff opener)."

The Yankees backed Severino by getting another big night from Didi Gregorius, who tied a season high with four RBIs. He hit the first of his sacrifice flies off Baltimore starter Gabriel Ynoa (1-2) and blasted a tiebreaking two-run homer off Miguel Castro in the fifth.

Gary Sanchez and Chase Headley added RBI singles during a three-run seventh, and Greg Bird capped New York's latest win over the Orioles by reaching the second deck in right field with his fourth homer of the season.

The Orioles did little besides Castillo's 20th homer and lost for the eighth time in nine games. They committed a pair of errors, including one by Chris Davis, who allowed a ball to trickle off his glove at first base in the second inning. They have allowed 141 runs to the Yankees this season, with 91 of those runs occurring at Yankee Stadium.

"It's a combination of us not swinging it well and them really pitching well," Baltimore manager Buck Showalter said. "I mean that's a deep rotation and a deep bullpen, that's why they are where they are."

Manny Machado nearly was ejected by plate umpire Paul Emmel in the first inning following a strikeout on a check swing. In the sixth, he slammed the bat on his leg after popping up on the first pitch.

Ynoa lasted 4 1/3 innings and was charged with three runs (two earned) on five hits.

NOTES: The Yankees were fined an undisclosed amount by commissioner Rob Manfred for violating a rule governing the use of a dugout phone. Manfred said in a statement that the money is getting donated to hurricane relief efforts in Florida. ... Baltimore CF Adam Jones received the night off. Manager Buck Showalter said Jones seemed tired in his legs after playing a three-game series on Toronto's artificial turf. ... The Yankees honored former executive Gene "Stick" Michael with a moment of silence and a video tribute after being unable to do so Thursday due to technical difficulties with the scoreboard. Michael, who was the GM of the Yankees from 1991 to 1995, died last week. During the ceremony, Showalter, Joe Girardi, Willie Randolph, Paul O'Neill and David Cone placed wreaths at home plate.