An elated Navin Shah was inducted into the Greater London Assembly on May 2 after one of the closest-run constituency battles of the London elections.
The Labour candidate narrowly defeated his Conservative rival Bob Blackman by 1,649 votes, cementing his place at City Hall for the next four years.
Mr Shah was joined by his campaign team and family for the 12-hour long electronic count at Alexandra Palace and managed to buck the national trend of heavy Labour losses in the recent local elections.
Speaking after the 9.30pm result, he said: "I am absolutely elated. This is a superb result for Brent and Harrow and I am most grateful to the people for their confidence and trust. I will not let them down.
"It shows people have sussed out that the Liberal and Tory administrations in both boroughs do not deliver."
Mr Shah's 22-year-old son Neil, who had helped his father with his campaign, added: "I can't believe it. I feel justice has been done. It's like your football team winning the league!"
Both Labour and Conservative candidates saw increases in the number of votes cast for them compared with the last elections. The result was agonisignly close, with Mr Shah winning 37 per cent of the vote and Mr Blackman, who won the 2004 election by 4,500 votes, this time winning 36 per cent.
Liberal Democrat candidate James Allie came third with 12 per cent of the vote. The Green party saw a marked increase but still came in fourth with 6.5 per cent.
Mr Shah, who spent the majority of the count away from the constantly updated results screen, will now step
down as leader of the Harrow Labour group in June to concentrate on his GLA duties.
After the result, defeated Mr Blackman, who had lost a stone in weight during the gruelling campaign, said: "We have gone up from 34,000 votes last election to 56,000 but that is the way that it goes. I will continue to dedicate myself to uniting communities and fighting all forms of racial hatred.
"Maybe other candidates should consider their positions."
Just over 40 per cent of the Harrow and Brent population headed to polling stations on May 1 - the borough's biggest turnout since the London elections began.
