Labour took three Welsh seats from the Conservatives as Theresa May's party failed to achieve its hoped for breakthrough.
Jeremy Corbyn's party won Gower, Vale of Clwyd and Cardiff North.
Gower, won by the Tories in 2015 after more than 100 years in Labour hands, was the most marginal seat in the country with a majority of 27 for Tory Byron Davies.
On Friday morning, Welsh Labour candidate Tonia Antoniazzi won 22,727 votes while Mr Davies got 19,458, a majority of 3,269.
Ms Antoniazzi said the last six weeks had been the best of her life and added: "I promise to you that with every fibre of my body I will work tirelessly to give you the representation that you and your family deserve."
Mr Davies said he had "thoroughly enjoyed" his two years as member of parliament for Gower.
Vale of Clwyd was another Conservative win in 2015, while Cardiff North has been held by Theresa May's party since 2010.
A Welsh Labour spokesman said it was "increasingly clear that Welsh Labour's campaign has connected positively with voters across Wales".
He said: "Given that at the beginning of the campaign polls put us ten points behind and losing more than ten seats, this is a remarkable turnaround, and shows the strength of our Welsh Labour campaign."
He added that it was "clear that the Tories are having a terrible night in Wales".
"They are not just failing to take seats – they are losing them, and seeing majorities slashed elsewhere," he said.
The Conservatives also failed to take Wrexham, which they had hoped to win.
A Tory source said that result was "truly disappointing for the party in Wales and must be heartbreaking for Andy Atkinson, who campaigned with all his heart for that seat".