George Galloway has described his victory in Bradford West as the most "sensational victory in by-election history, bar none", but was it?
The Respect Party MP snatched the seat, a Labour stronghold since 1974, with a huge swing of 36.59%.
Galloway won 18,341 votes or 56% share of the total vote. Labour candidate Imran Hussein came a distant second with just 8,201 - down 20% on what the party secured at the 2010 general election.
While the swing was impressive, it is not quite the biggest ever seen. Here is a short history of other notable by-election shocks.
1967: Winifred Ewing snatched a seat for the Scottish National Party, when she turned a 16,576 Labour majority at Hamilton into a 1,799 nationalist one. She polled 46% in a constituency previously uncontested by her party.
1968: Tories chalked up a 21.1 % swing to take Dudley on March 28 from Labour as well as marginal Meriden and Acton. This was possibly the first time in history that a party lost three seats at by-elections on the same day.
1969: Liberals captured Ladywood, their first Birmingham seat for 83 years, from Labour on a 32% swing. The two years from November 2 1967 to Oct 30 1969 brought Labour its worst by-election run. The party lost 10 seats during that time and the swing against it was never less than 10%.
1972: Liberals overturned a 12,696 Conservative majority to win Sutton and Cheam on a 32.6% swing.
1976: Tories gained Walsall North on a 22.5% swing after the imprisonment of former Labour minister John Stonehouse.
1977: The Conservatives toppled Labour in its Ashfield mining stronghold on a 20.8% swing.
1983: Liberal Simon Hughes gained the highest swing since the Second Word War - 44.2% - when he won Bermondsey from Labour.
1988: Jim Sillars grabbed Glasgow Govan for the SNP on a 33.1% swing from Labour, emulating the victory in the same area of his wife Margo MacDonald 15 years before.
1993: The first by-election of the new parliament saw Liberal Democrats capture Newbury from Tories with 22,055 majority on a 28.4% swing. This was followed by the Christchurch contest which brought the biggest recorded swing against a Government - 35.4% from Conservative to Liberal Democrats.
FULL COVERAGE OF GALLOWAY'S BRADFORD WEST WIN
1997: With the General Election barely two months away, Conservatives lost to Labour at Wirral South on a 17.2% swing. Tories failed to win a single by-election between William Hague's victory at Richmond, Yorks in 1989 and their success in the first contest of the new 1997 Parliament at Uxbridge.
But this was short-lived when Liberal Democrat Mark Oaten won the Winchester poll, a re-run after the General Election result was declared void, with a 21,556 majority on a 19.8% swing.
2000: Liberal Democrats took Romsey, next door constituency to Winchester, turning an 8,585 Conservative majority into one of 3,311 for themselves on a 12.56% swing. This was the first time for 35 years that Tories had lost a seat at a by-election in Great Britain when they were in Opposition at Westminster.
2003: Labour suffered its first Commons by-election loss since it returned to power in 1997 when Liberal Democrats snatched Brent East, north London on a 29% swing.
2008: Mr Brown, now Prime Minister, was hit by Tories' first Commons by-election gain in more than a quarter of a century when they took Crewe and Nantwich on a 17.6% votes turn-round. Two months later Glasgow East became the second so-called 'safe' seat lost by Labour on Mr Brown's watch. The switch to the Scottish National Party was 22.5%.
2009: Tory Chloe Smith became the youngest MP when she snatched Norwich North from Labour on a 16.5% swing.