Politics student Mhairi Black, representing the pro-independence Scottish National Party (SNP), took Paisley and Renfrewshire South, a constituency outside Glasgow, from Douglas Alexander, Labour's election chief and a former Cabinet minister.
"It has clearly been a very difficult and disappointing night for the Labour party," Ed Miliband told supporters as he retained his own seat. He cited a "surge of nationalism in Scotland" as having affected the Labour party's results.
Scotland, traditionally kind to Labour, turned it back on the Opposition in favor of the SNP.
Labour's Scottish leader, Jim Murphy, lost his parliamentary seat to Kirsten Oswald, another largely unknown challenger, while former British Prime Minister Gordon Brown's old seat also went to the nationalists.
The SNP's Alex Salmond, who led Scotland as First Minister and pushed for the unsuccessful independence referendum last year, won a seat at Westminster.
But the night belonged to an ecstatic Black.
"I pledge to use this voice not just to improve Scotland, but to pursue progressive politics for the benefit of people across the UK," she told supporters during her acceptance speech.
The Liberal Democrats, junior partners in the previous coalition government with the Conservatives, also lost some key figures -- chief among them Danny Alexander, Chief Secretary to the Treasury; Vince Cable, the Business Secretary; and Simon Hughes, a former London mayoral candidate. Current leader Nick Clegg, who was Deputy Prime Minister, held his seat.
By contrast, the Conservatives were touted to make big gains with no real surprises so far -- Prime Minister David Cameron held his seat, while London Mayor, Boris Johnson, won a place in parliament.
Two British broadcasters have adjusted their forecasts, with CNN affiliate ITN suggesting Cameron's Conservatives will win an absolute majority of 327. The BBC is forecasting 325 for the Conservatives. That would also be enough to govern alone -- parties need at least 323 seats to achieve an absolute majority.
Even though the final tally isn't in, one thing is clear: This is an election you should be paying attention to, even if you're not one of the millions of Brits who cast a ballot.
The vote could reshape the country's global role for years. Britain's relationships with the European Union, NATO and the United States are hanging in the balance. And a boost for the Scottish National Party could fuel a fresh push for Scottish independence.
'Most important election in a generation'
Before the vote, Cameron
called it "the biggest and most important election in a generation." And this time, that age-old political rallying cry could actually turn out to be true
As he campaigned this week, Cameron touted what he said was the country's economic recovery under his Conservative leadership. "I've now laid my brick," he said, claiming that the big payoff is yet to come for Britain as the country builds on the work he's done.
He said that if he was re-elected, he would hold a referendum on Britain's membership in the European Union.
On the other side, the Labour Party's Ed Miliband -- who prides himself in standing up to U.S. influence -- had promised higher taxes on the wealthy and the protection of Britain's public health system.
"We're fighting for a Britain where we reward the hard work of every working person," he said this week, "not just those who get the six figure bonuses in our country."
A total of 650 members of Parliament will be elected, representing constituencies across England, Scotland, Wales and Northern Ireland. Whichever political party has the most members of Parliament
elected will be invited by Queen Elizabeth II
to form a government. If there's no clear winner, then a minority or coalition government may be formed.
Many observers had predicted no clear winner and suggested there would be days of post-vote, back-room talk to thrash out a power-sharing deal.
But with exit polls pointing toward a more decisive result, British tabloids quickly seized on with their Friday front pages.
The Daily Mirror lamented the projected Conservative victory.
The Sun took a more triumphant tack, with a smiling photo of Cameron front and center.
'An electoral tsunami'
Alex Salmond, the party's former leader, said no matter what the final tally is, the result is clear.
"We're seeing an electoral tsunami on a gigantic scale," he told ITN, "and that is a tide flowing with the Scottish National Party."
A big win for the party could accelerate the resurgent momentum toward another Scottish independence referendum in the years to come.
But gaining independence for Scotland isn't the only issue on the Scottish National Party's agenda. They also want to end Britain's nuclear weapons program, which could have an impact on the country's relationship with NATO.
, its leader and the winner of much acclaim during the campaign, has vowed not to form a pact with the Conservatives, but her past overtures to the Labour Party have been rebuffed.