These were awful results for the Conservatives, among their worst by-election defeats since 1945.
The biggest collapse took place in Tiverton and Honiton. The outcome there establishes a new record: the largest Conservative percentage majority overturned in a by-election.
It replaces Shropshire North in the top spot, confounding Tories who mistakenly thought that things couldn't get worse after that mauling.
The swing to the Liberal Democrats in Tiverton is 29.9%. Not the worst, with the catastrophe that was the Christchurch by-election still heading the list.
But this latest result becomes the sixth-worst swing from the Conservatives to the Liberal Democrats and its predecessors in the post-war era.
Comparisons with by-election turnarounds during the Conservatives' slow-motion advance to disaster at the 1997 general election are certain to concentrate the minds of its MPs representing seats across southern England.
No one expects the Liberal Democrats to meet with the same success at the next general election, but it certainly appears that many have now forgiven the party for joining David Cameron's coalition government.
Labour's long wait to take a Conservative seat at a by-election is finally over. The last time Labour gained a seat was in Corby in November 2012.
Coincidentally, the swing then was the same - 12.7% - as in Wakefield, which becomes the seventh-worst Conservative defeat to Labour.
Sir Keir Starmer's Labour is still a long way short of inflicting the pain dealt by Tony Blair's New Labour in the mid-1990s.
But victory in Wakefield has huge symbolic value.
It demonstrates that Boris Johnson's 80-seat Commons majority - constructed largely from its gain of Labour's so-called "red wall" seats, including Wakefield, is vulnerable.
An outright Labour win at the next general election, however, remains a remote possibility.
Labour needs a 12% swing to win a majority of just two, assuming the next election is fought on current constituency boundaries.
That is larger than what Tony Blair achieved in winning a landslide in 1997, and not far short of the Wakefield swing, which we should discount because it was a by-election.
But there is something else about these results that should send fear throughout Conservative ranks: the Liberal Democrats won in Tiverton because of the large-scale desertion of Labour voters.
Labour's win in Wakefield was assisted by the absence of a serious Lib Dem campaign.
Following these results, it's likely we shall hear more talk about electoral pacts and/or tactical voting as the best method for expressing anti-Conservative sentiment.
For that reason, these two by-elections - held on the sixth anniversary of the EU referendum - cannot be dismissed as simply a consequence of the unpopularity that all governments experience at the parliamentary mid-term.