SHANGHAI — Long after midnight Friday, as Klay Thompson signed autographs in front of the Ritz-Carlton hotel in this densely populated city, a young man in a black hoodie muscled his way toward the front of the scrum.

In his hand was a yellow toaster. Months earlier, after a picture of Thompson signing a fan’s toaster went viral online, many credited the kitchen appliance for the Warriors’ 31-2 run to an NBA title. Now, more than 6,000 miles away from the Bay Area, Thompson chuckled as he jotted his signature on another toaster.

It was a funny scene, but not all that surprising. The Warriors were treated more like rock stars than athletes during their three days in Shenzhen. Since arriving in Shanghai early Friday, Golden State has seen fans’ fervor only intensify.

The swarm of supporters in front of the team hotel, which mostly ranged from three dozen to four dozen in Shenzhen, has hung steadily in the low hundreds in Shanghai. While fans in Shenzhen headed home once the Warriors had seemingly gone to bed, their counterparts in Shanghai stay around the clock to catch a glimpse of their favorite players.

Now Playing:

The young man with the yellow toaster was hardly the only die-hard to come prepared. Many of Golden State’s fans in Shanghai have worn backpacks to the hotel, dipping into their bags whenever a different player approaches. One especially diligent fan brought jerseys for Thompson, Stephen Curry, Draymond Green, Kevin Durant — and, just in case — Jamal Crawford, who is staying at the same hotel, with the Timberwolves.

“The stuff we’ve seen has been pretty crazy, man,” guard Patrick McCaw said. “It’s something I’ll never forget.”

The Warriors have made a point in China not to let training camp keep them from interacting with their biggest international fan base. After exorcising the memory of Thursday’s exhibition loss to Minnesota with a long practice Friday, many players ventured into the city to shop, eat or — in the case of Durant and Green — hold meet-and-greets.

Durant’s Nike-sponsored event came at a middle-school gymnasium, where he chatted with fans, hit a halfcourt shot and handed out 180 T-shirts. After watching Durant bank in a heave from midcourt on just his third attempt, attendees rained down a “KD!” chant on the NBA Finals MVP.

Twenty minutes before Green’s scheduled arrival Friday evening at a New Era store in a local mall, more than 100 fans waited behind barricades. The half-hour event included several photo opportunities and a short question-and-answer session.

“It’s been an amazing trip,” said Green, who is visiting Shanghai for the third time. “The love we have in China, it means so much.”

In a country that boasts an estimated 300 million basketball players, Shanghai is a hoops epicenter. It was on these blacktops that Yao Ming developed his signature sky hook. His rise from spindly 13-year-old on the Shanghai Sharks’ junior team to No. 1 pick in the 2002 NBA draft to eight-time NBA All-Star took the league’s presence in the city to another level.

Shanghai has hosted seven NBA exhibitions since 2004. Now president of the Chinese Basketball Association and owner of the Sharks, Yao — who is expected to attend Sunday’s Warriors-Timberwolves matchup — has organized preseason games each of the past two years between his hometown club and his former NBA team, the Rockets.

“Basketball is big everywhere in China, but you’d be hard-pressed to find a place that loves it more than Shanghai,” said Xiaoche Sun, who covers the NBA for China Daily, an English-language newspaper based in Beijing. “That has a lot to do with Yao. Before he came around, basketball was something Chinese people did. Now it’s a passion.”

Six years after Yao played his last NBA game, the Warriors are the franchise of choice in Shanghai. Curry, Durant and Thompson had three of the top-10 jerseys sold in China this past year on NBA.com. When tickets to Golden State’s exhibition against Minnesota went on sale Aug. 18, they sold out within an hour.

After signing 10 hats for fans Friday at his New Era appearance, Green — at best, the fourth most-popular Warrior in China — followed two team staffers and a half-dozen Chinese security guards out the back door. Navigating the crowd would’ve risked mayhem.

“This is a city that never disappoints,” Green said. “The food is incredible, but the people are even better.”

Connor Letourneau is a San Francisco Chronicle staff writer. Email: cletourneau@sfchronicle.com Twitter: @Con_Chron