LONDON — Julian Bysouth traveled often on vacation from England to the United States, which is how he happened to be in a bar in St. Mark’s Place on Oct. 21, 2000, and found himself transfixed by what everyone was fervently watching that evening.

That would be Game 1 of the 2000 World Series, Mets-Yankees. That would start a love affair with baseball — specifically the Yankees — that would have the London native standing on Thursday afternoon 3,500 miles from that bar wearing an Andy Pettitte jersey while in front of the Yankee who started that Subway Series Game 1 — that would be Andy Pettitte. Bysouth had an interlocking “NY” tattoo on his right wrist and his 8-year-old son, Shea — yeah, like the stadium — standing by his side.

It was the it’s-a-small-world dream snapshot for MLB.

For the Yankees are in London to serve two purposes: 1) to play a pair of games against the Red Sox, and 2) to sell a sport with a small footprint in this country and on this continent. The games will be at London Stadium. But the Yankees’ first victory came at Finsbury Park — where they ran a clinic for roughly 100 kids who are part of the London Mets Baseball & Softball club, which sponsors teams from age 10 to adult.

“It really is our job to do both,” Hal Steinbrenner said.

The Yankees often earn their distinction for cold distance and a sense of being above the sport. But they were wonderful ambassadors for their brand and their game Thursday. Most of their key executives were present — as was an alumni contingent of Pettitte, Carlos Beltran, Reggie Jackson, Hideki Matsui, Mariano Rivera, Alex Rodriguez and Nick Swisher. It moved Commissioner Rob Manfred to tell the crowd, “You don’t get a group like this for an event in the United States.”

That the players plus Aaron Boone invested not just in the handshakes and autographs, but also in the 90 minutes of base running, fielding and hitting made this an event that creates lifelong fans. Which is, of course, the idea.

These will be the first major league games in Europe, and as Yankee president Randy Levine said, “If you come here, you have to lead with your best.” That would be the Yankees and Red Sox, of which Steinbrenner explained, “It is the right two teams. It is the greatest rivalry in baseball. We have played more than 2,000 games. We have played more than 100 years. And it often has been contentious.”

On Thursday, though, the Yankees went alone. Steinbrenner had sought for his team to do something community based, and with the assistance of their partner, Manchester City, found the London Mets and the only permanent fields in London. But let’s just say those diamonds are not well known.

Finsbury Park is large, about a quarter of the size of Prospect Park, and I entered the south side, and even police and park employees were not fully aware of where the fields — or “pitches” as I hopefully helpfully offered — were.

This is why MLB and two of its mega-powers are here. MLB and officials from the London Mets say there is growing interest and participation in the sport here. MLB wants to open markets for potential future talent, but always for dollars purposes — to get folks to watch the games and buy the merchandise. The games Saturday and Sunday are sold out, MLB officials say. And this clinic was a success in positively spreading the word.

It was Julian Bysouth and Shea. It was Steinbrenner walking Benjamin Mills-Knutsen over to Brian Cashman and telling the Yankees GM that he was the only person at the event the 12-year-old wanted to meet. Cashman said he hoped he would work for Mills-Knutsen some day and handed him a World Series ring: “When you win your World Series, you will get one of these.”

It was the Yankees removing a tarp from the side of a truck to reveal about $35,000 worth of equipment they were donating to the league, and most of the players mingling as part of the hamburgers/hot dogs barbecue that concluded the event.

It was about the spirit and goodwill the Yankees infused into the event and, really, this whole trip. The players were not uniformly excited to open the 2004 season in Japan. But the vibe this time is different, more enthusiastic, more embracing.

“They want to make history,” assistant GM Jean Afterman said. “It’s always exciting to be first. It does break up the monotony of the season to fly across The Pond.”

They landed as a first-place team and in their initial group act were first-class diplomats. This league is growing, according to officials of the London Mets, and not just with ex-pats from America and Japan, but with more native Britons picking up the sport. The Yankees did well to make lifelong fans of the game and their team over a few hours on the only two permanent baseball diamonds in London.

“It’s a seed right now,” Steinbrenner said. “You have to water it. You have to promote it. Hopefully, we are doing that well. And who knows what it looks like in England and Europe in 10 years.”