NEW YORK -- Good morning from the corner of 49th and Lex in a city where, for one day at least, the tabloids are hailing the Mets as kings and deriding the Yanks as “Bronx bums” after the Mets won big and the Yanks took it on the chin from the Sox on Monday. It was the first time since 1957 that two New York teams opened at home on the same day.

For the first time in 579 days, the Red Sox stand alone in first place in the American League East, a position they last occupied on Sept. 1, 2011, when Terry Francona was manager, Josh Beckett was the ace and Bobby Valentine was in an ESPN broadcast booth.

Now, Tito is a best-selling author and managing the Indians, Beckett is pitching at the back end of the Dodgers rotation, and Valentine, after a forgettable interlude managing the Sox, is back in another broadcast booth, this one belonging to SportsNet New York, where he will offer analysis of Mets games.

By nightfall, the Sox will have company at the top. The Orioles and Rays open against each other this afternoon, while the Sox are off, their next game scheduled for Wednesday night in the Bronx. Clay Buchholz is scheduled to make his first start against Hiroki Kuroda. But you take what you can get, and for the Sox, there’s no downside to being undefeated, even for just a day.

With a break in the schedule, this is a day to tell a couple of smaller stories from Opening Day, ones that don’t involve the celebrated debut of a 22-year-old Sox rookie who has a chance to be something special, even if no one should confuse Jackie Bradley Jr. with the second coming of Willie Mays, as one biting tweeter reminded.

The day resonated for Bradley, but it meant something, too, to a baseball lifer who waited 26 years to become a big leaguer, and for a 27-year-old pitcher who had never experienced the thrill of being introduced and taking his place alongside his teammates the day it all begins.

Red Sox first-base coach Arnie Beyeler was an all-conference infielder at Wichita State and played minor-league ball for six seasons with the Detroit Tigers, spending one year in Class A as a teammate of Sox bench coach Torey Lovullo. A second baseman and shortstop, Beyeler made it as high as Triple-A in 1991, but would go no higher as a player. He became an area scout for the Tigers, was hired as a minor-league hitting and infield coach for the Yankees, landed his first minor-league managing job with short-season Lowell for the Sox in 2000, was let go by the Sox as Class A manager after the 2002 season, managed in the low minors for the Rangers, spent 2006 as a hitting coach in Double-A for the Padres, then wound up back with the Sox in 2007, when he became manager at Double-A Portland.

He took the Sea Dogs to the playoffs twice, then last fall won the International League championship for Triple-A Pawtucket, who also went to the playoffs under Beyeler the year before.

He had logged more bus miles than Greyhound, spent countless nights in economy hotels where they leave the lights on for you, and had learned to subsist on meal money where it’s considered splurging when you buy the Grand Slam breakfast with an extra side of bacon.

That all changed last November when the phone rang and John Farrell asked Beyeler to be his first-base coach. Beyeler had been in a big-league clubhouse before, having spent time with the Sox in September after his minor-league season was over, but he’d never spent an April morning in the third-base dugout in Yankee Stadium, waiting to hear his name being called.

His daughter, Jordan, a dancer with a modern-dance company in Chicago, had flown in the day before, a surprise arranged by Beyeler’s girlfriend. His high school coach flew in on his own from Utah, where Beyeler was born (Moab). His cousin showed up.

Jordan was a Yankee fan. So was the high school coach.

“Her boy Jeter wasn’t here,’’ Beyeler said. “She was bummed about that. She used to watch games here with me when she was a little girl, and I was working for the Yankees.’’

But on this day, Jordan was first and foremost an Arnie Beyeler fan, and watched as her 49-year-old father trotted out to the line and stood next to hitting coach Greg Colbrunn.

“When we got introduced and me and Colby were standing out there,’’ Beyeler said, “I started thinking, like I did when John called me this winter, about all the people who have helped me along the way. It was pretty neat and it still is.

“I’m blessed to do what I do and to know the people I have been fortunate to have had contact with, who got me where I’m at. People like Butter [bench coach Brian Butterfield] and John and Torey, these guys I learn from every day. And the guys on the other side of the field, Robby Thomson and Mick Kelleher and Mark Newman and Gary Denbo, all those Yankee guys who helped me when I started.

“It was real special for me, Opening Day at Yankee Stadium. It couldn’t have been better anywhere else, for someone with my history.’’

Like Beyeler, Clayton Mortensen hails from the Pacific Northwest. He grew up in Idaho (Rexburg), played junior college ball in Oregon, then transferred to Gonzaga, where the Cardinals drafted him as a first-round sandwich pick in 2007, the highest any Zag had ever been drafted.

But within five years, Mortensen was traded three times. The Cards sent him to Oakland as part of the big Matt Holliday deadline deal in 2009. Two years later, the Athletics shipped him to Colorado, and a month before spring training in 2012, the Rockies sent him to Boston for Marco Scutaro.

Last season, he wore out the Pawtucket shuttle. He was summoned six times to the big leagues by the Sox, the longest stint lasting three weeks in August before his final recall on Sept. 4, when he finished out the season. When he was here, he pitched pretty well, striking out six A’s in three innings in his Sox debut May 2, then ringing up 5 more K’s in 3 1/3 innings in his next outing, against the Orioles.

Overall, he posted a 3.21 ERA in 26 appearances, striking out 41 batters in 42 innings. The right-hander was not overpowering, but he had deception, a “different-acting slider,” as Farrell called it, and this spring broke out a changeup he had used infrequently in the past.

Mortensen also was out of options, meaning the Red Sox either had to keep him or expose him to waivers, giving another team the chance to claim him, an opportunity another club almost certainly would have exercised. He came down to the final days of camp not knowing whether he’d be sticking with the Sox.

“For the most part you try almost to be numb to it,’’ Mortensen said of the uncertainty. “You go about it like it’s not there, it doesn’t exist, but it definitely was there. It’s definitely a kind of stressful spring training.’’

Mortensen and his wife, Janna, have a son, Miles.

“At the very end, your wife, whatever, they hear things,’’ he said. “They’re always worried, which makes me worry. I just told my wife and my family, ‘It is what it is. If I make the team, I make the team. If I don’t, I might go somewhere else. That’s just the way it is. It’s out of my control. I’m just trying to pitch, just trying to get people out. If I do that, I feel like I have a good shot at making it.’’

Late last week, the Red Sox announced that they were sending Daniel Bard back to the minors to keep working on his delivery. With left-handers Franklin Morales and Craig Breslow beginning the season on the disabled list, that opened a roster spot for Mortensen.

On Monday, for the first time in his career, Clayton Mortensen began a season in the big leagues.

“That was huge,’’ he said. “I’ve been called up a few times over the last few years, so pitching in the big leagues is not like a whole new thing.

“But making an Opening Day roster is a little bit different, especially for the Boston Red Sox. Not many people can say they’ve done that before, so yeah, it was pretty special. My family is pretty proud, which is cool.’’

Mortensen knows the uncertainty is not very far away.

“It’s to the side right now,’’ he said. “I’m aware there are two guys here who have to come off the DL in a little bit, but until that time happens, I can’t think about that. It would probably affect my pitching out there.

“All I can do is take care of my business. When something happens, something happens.’’

But for one day, for Arnie Beyeler and Clayton Mortensen, it was all good.