Trumpets sounded, cheers reverberated and even burly workers wiped away tears as foreman Hubert Baer lifted a statue of Saint Barbara - the patron saint of miners - through a small hole in the enormous drilling machine thousands of feet (meters) underground in central Switzerland.
At that moment, a 35.4-mile (57-kilometer) tunnel was born, and the Alpine nation reclaimed the record from Japan's Seikan Tunnel. Television stations across Europe showed the event live.
"This is the most wonderful moment in my 36 years of tunnel building," Baer said as he paused for breath, surrounded by joyous colleagues in hardhats and bright orange work gear, VIPs and news cameras.
The new Gotthard Base Tunnel is seen as an important milestone in the creation of a high-speed transportation network connecting all corners of Europe.
First conceived in 1947 by engineer Eduard Gruner, it will allow millions of tons of goods that are currently transported through the Alps on heavy trucks to be shifted onto the rails, particularly on the economically important link between the Dutch port of Rotterdam and Italy's Mediterranean port of Genoa.
The tunnel also aims to reduce the damage that heavy trucks are inflicting on Switzerland's pristine Alpine landscape.
Peter Fueglistaler, director of the Swiss Federal Office of Transport, called Friday "a day of joy for Switzerland."
"We are not a very emotional people but if we have the longest tunnel in the world, this also for us is very, very emotional" he told The Associated Press.
Some 2,500 workers have spent nearly 20 years smashing through the rock beneath the towering Gotthard massif, including the 8,200-foot (2,500-meter) Piz Vatgira (Vatgira Peak).
When the $10 billion tunnel opens for rail traffic in 2017, it will replace Japan's 33.5-mile (53.6-kilometer) Seikan Tunnel as the world's longest - excluding aqueducts - and let passenger and cargo trains pass under the Alps at speeds of up to 155 mph (250 kph) on their way from Germany to Italy.
Swiss voters, who are paying over $1,300 each to fund the project, approved its construction in a series of referendums almost 20 years ago.
European transport ministers watched the breakthrough ceremony live from a meeting in Luxembourg, conscious that Switzerland has set the bar very high for future cross-Alpine rail projects. Two further tunnels - one connecting connect Lyon, France, to Turin in Italy, and the other replacing the Brenner road tunnel between Austria and Italy - are still a long way from completion.
Swiss engineers are hoping to complete the rail tunnel even sooner than planned - possibly by the end of 2016 - but its first high-speed trains could be delayed by protests in Germany and Italy, where local opposition to new tracks and budget constraints have become an issue in recent months.
"Our neighbors in Germany and Italy will have to fulfill their promise and provide high-speed rail links," Fueglistaler said.
Asked whether he thought the large, ongoing protests in the German city of Stuttgart could derail the high-speed dream, he said: "Overall I'm confident that these connections will be built in time."
The protesters in Stuttgart oppose plans to move the city's station underground, viewing the euro4.1 billion ($5.7 billion) project as a waste of money. Supporters say it will free up the city's packed center and help shorten journeys across Europe.
Heinz Ehrbar, a bear of a man in bright orange overalls, told the AP the breakthrough celebration was also a moment to reflect on the lives lost during the Gotthard tunnel's construction.
"I'm really proud, but I'm thinking also of the eight people who have lost their lives," said Ehrbar, the tunnel's chief construction officer. "It's very important that we remember that not all of our workers can be with us today."