Labour has lost its 20-year grip on Middlesbrough South and East Cleveland to the Conservatives.
The constituency had been Labour throughout its 20-year history, until Thursday's election.
It was held from 2010-2017 by Tom Blenkinsop, and before that by Ashok Kumar from 1997.
Blenkinsop said he would not stand after Theresa May announced her snap election and Tracy Harvey had the job to hold the seat for Labour.
But she was beaten by Tory Simon Clarke by just 1,020 votes.
The constituency covers a mixed area that includes parts of urban Teesside, alongside seaside and rural communities in what was once the North Riding of Yorkshire.
It has been a key marginal - and a Conservative target - since 2010.
It had formerly been the Langbaurgh seat, held by the Tories from its creation in 1983 to 1997, although Labour snatched it for a few months at a by-election in 1991.
The Conservatives have been keen to get back on the map in this area ever since the Labour landslide of 1997.
Tom Blenkinsop was run close by Tory Paul Bristow in 2010 and wonby a majority of just 1,677.
In 2015 Blenkinsop increased his hold by 2.8 % beating Tory Will Goodhand with a majority of 2,268.