The towering hall thundered with the euphoria of a nation where everyone seemed, for the moment, to have left their differences behind.The celebrants spoke Zulu, Sotho, Tswana, Afrikaans and English. They were Black and white, young and old, mining company managers and restaurant waitresses.They sang and danced together to songs blasting from speakers. They waved South African flags. They wore the same green-and-gold attire of their rugby heroes as they gathered at the Oliver Reginald Tambo airport in Johannesburg on Tuesday to welcome the team home from the championship game in France. A bronze statue of Tambo with a hand aloft stood among the jubilation, as if bestowing his blessing upon a scene made possible by the work he did to topple apartheid.South Africa became the winningest country in the Rugby World Cup’s relatively brief history last week, claiming its second consecutive crown and fourth overall. This nation of 60 million has been going wild ever since.The revelry will reach a raucous peak over the next four days as the team begins a tour of the country, starting with parades through Pretoria, the executive capital, and Johannesburg on Thursday.“Unity,” is how Maureen Mampuru, 43 and Black, described the impact of the victory for the country — a description echoed by Martin Peens, 60 and white; Jacqui Vermaak, 56 and white; Happy Mthethwa, 40 and Black; Michelle Volny, 43 and white; and Gloria Leshilo, 34 and Black.The 2009 Hollywood blockbuster “Invictus” told the story of South Africa’s first victory in the Rugby World Cup in 1995, just a year removed from the start of democracy, and how it unified a racially divided nation. Back then, I chalked up all the lump-throated racial harmony the movie portrayed to Hollywood romanticism. I thought there was no way that a rugby victory could have had a real impact on the racial divide in a country fresh out of decades of legalized racism.But I’ve now lived in South Africa for the past two years and experienced the thrill of watching the Springboks, as the team is called, win a world championship while cheering along with the country’s rugby-obsessed population.The harmony that World Cup success produces, I can report, is no exaggeration.When the final whistle blew last Saturday, and South Africa had eked out a tense 12-11 victory over New Zealand, celebrations erupted across the spectrum of present day South Africa: from bars in the somewhat gritty townships of Soweto to the outdoor plaza at a posh shopping center in Pretoria to the bar where I watched the game in an affluent northern suburb of Johannesburg.There, Black and white fans soaked up the victory together. Some wrapped their arms around each other. Others shouted a popular Zulu chant sung at sporting events: “They’ve never seen one like him!”“I’m reliving ’95,” Francois Pienaar, who was captain of the 1995 South African squad, said in a phone interview. For years, the national rugby team had, by the apartheid government’s design, been seen as the preserve of the country’s white minority. But 1995 was the first time that Black fans rallied around the team en masse.“It’s about more than just rugby,” Mr. Pienaar said. “It’s about a nation. It’s about hope. It’s about building a future for everyone in our country.”At the airport on Tuesday, a white family held up a sign that read, “Siya for President,” a reference to Siya Kolisi, whose life reflects freedoms once unavailable to Black South Africans. He is the first Black captain of the national rugby team, is in an interracial marriage and, after the victory, posted a video to Instagram of him and several white teammates singing a popular rallying chant in Zulu that essentially says they are brothers.That sort of rallying together, especially around race, was similar to 1995, John Carlin, the author of “Playing the Enemy,” the book that inspired the film “Invictus,” said in an interview. That World Cup was basically the first time that Black and white South Africans “were united in one purpose and one goal,” he said, adding that “it was astonishing to behold.”But there are crucial differences between 1995 and now.Back then, many South Africans were bubbling with hope that under a new democracy and a new president, Nelson Mandela, they could achieve shared success.“Winning the cup in 1995 put a stamp on it that we can work together if we just listen to one another,” said Ms. Mampuru, who works as an administrator for a political party. “If we just respect each other, we can do much more together as one.”Now, though, the population has had time to soak in the many failures of the democratic promise over the past decades. Corruption, poor leadership and entrenched apartheid-era disparities have left the country battling many crises. Electricity is unreliable. Unemployment and crime rates are high. Race continues to determine where many people live and their experiences in school.The country’s troubles are so enormous that, for many, this Springboks victory feels like a much-needed escape, and has inspired celebrations that many believe are more intense than ever.After watching the game at the bar, I rolled down the windows of my car and drove slowly through a busy street on my way home late at night. Fans crowded in on either side, wielding phones to capture the moment. All the warnings of vigilance about carjacking or cellphone snatching seemingly had been forgotten. Everything felt at ease.“We really hope this doesn’t end at a little bit of celebration for a week,” Mr. Kolisi, the team captain, said after touching down in South Africa. “It needs to do more.”The governing African National Congress, a once-lauded liberation movement that has shouldered much of the blame for South Africa’s present struggles, wasted no time trying to get political mileage from the win before next year’s national elections.The morning after the victory, the A.N.C. released a statement congratulating the team and applauding “the pioneering leadership by President Cyril Ramaphosa.” Fikile Mbalula, a top A.N.C. official, wrote on Twitter that Mr. Ramaphosa was the only “two-time rugby World Cup champion President.” Mr. Ramaphosa held a nationally televised, prime time address on Monday in which he congratulated the Springboks before going through a laundry list of the accomplishments of his government, and then declaring Dec. 15 a public holiday.No amount of excitement or backslapping, though, can mask the cold reality of South Africa’s challenges.The day after the finals, power cuts to relieve the overburdened electricity grid returned for the first time in 10 days and have come every day since. Four days after the game, the country’s finance minister delivered a grim budget report that portended difficult spending cuts.When I asked a security guard in my neighborhood whether he had watched the game, he flashed an exasperated grin. His neighborhood in a predominantly Black township had been without power for two weeks, so he could only listen on his phone. But he shrugged it off. South Africa was No. 1 in the world at something, and he was happy about that.