Both of Harrow's seats were held by the incumbent MPs - but with vastly differing majorities in an unusually rapid count at the borough's leisure centre.
Labour and Co-operative Party member Gareth Thomas gained thousands of votes in Harrow West from the last General Election in 2015.
He told getwestlondon : "I'm really surprised and I'm really honoured, this is a seat that I grew up in and went to school in and lived in all my life.
"So to be reelected is a huge honour and I'm almost lost for words."
But the Labour-Conservative majority narrowed even tighter than 2015 in Harrow East, where Bob Blackman was reelected for the Tory party.
Voter turnout increased in both constituencies, with 71.07% hitting polling stations in Harrow East, and 72.33% in Harrow West.
A shell-shocked Gareth Thomas was "blown away" to receive 30,640 votes, a staggering 8,755 more than the previous election.
Mr Thomas added: "I'm a bit blown away by that is the honest truth, I never expected that to happen at all.
"At the outset of the campaign, we knew the Conservatives were pushing very hard to take the seat so to be reelected is what I was hoping to achieve, but to get a bigger majority is just great."
Although Mr Blackman received 25,129 votes, an increase of 461, the seat margin narrowed with Navin Shah just 1,757 votes behind him, gaining 23,372 votes for the Labour Party in Harrow East.
He told getwestlondon : "I'd like to thank the people of Harrow East for agreeing to reelect me as their representative.
"I'm looking forward to serving them in Parliament over the next five years, as their Member of Parliament, as I have done for the last seven years.
"I'm delighted with the result, I've produced an increase in my vote, and quite clearly held off this Labour surge which is said to have taken place across London."
Bitter disappointment was in the air for Conservative Hannah David, who lost 2,351 votes from the previous election, and ending up 13,314 votes behind her Harrow West rival, Gareth Thomas.
Tangible upset was felt as Navin Shah gave his closing speech with shouts of "the true winner" erupting from the mainly Labour-supporting crowd at the count in Harrow Leisure Centre.
Earlier in the evening, it was also revealed that the Green Party considered standing down in Harrow West - but Labour's denial of a progressive alliance meant they were told to run.