Manhattan real estate mogul Donald Trump officially became the Republican Party's presidential nominee on Tuesday after a roll call vote overshadowed by dissent and apathy, media reports said.
Trump sailed to the 1,237-delegate threshold, with his home state of New York putting him over the top, Politico reported.
The results were declared on the second day of the Republican National Convention (RNC) here after Trump's son, Donald Trump Jr., announced the 89 delegates that formally clinched the nomination.
"It is my honour to be able to throw Donald Trump over the top in the delegate count tonight with 89 delegates," Donald Jr. said, surrounded by three of Trump's other children -- Ivanka, Eric and Tiffany.
"Congratulations Dad, we love you."
Donald Trump himself tweeted that it was a "great honour" and vowed not to let the country down, Politico added.
"Such a great honour to be the Republican Nominee for President of the US," he said. "I will work hard and never let you down."
The business magnate's official nomination is a new apex in the political outsider's campaign to shake up Washington.
His White House bid began last June with a widely panned, rambling speech in which he blasted Mexicans as "rapists" and pledged to build a wall on the southern border that Mexico will pay for, Politico noted.
Donald Trump's campaign has seemingly endured strife almost daily since its inception.
Republican leaders were slow to back his campaign and have continued to condemn his controversial rhetoric and actions. But his message has resonated with an overwhelming number of voters who have propelled him atop the Party.
Indiana Governor Mike Pence was also formally nominated on Tuesday night as the Republican Party's choice for Vice President.
Particularly outraged with the result was the Washington, D.C., delegation, which held its convention in March and attempted to award 10 votes to former hopefuls Marco Rubio and nine to John Kasich. But convention officials announced the rules merit Trump be award all 19 delegates from the nation's capital, NBC News reported.
"This is an outrage, and this is a reason the Republican Party is turning off a lot of voters," a Kasich delegate from Washington D.C. told MSNBC.
After Trump had clinched the nomination, the Alaskan delegation contested how its vote total was recorded. They originally requested 12 votes go to Ted Cruz, 11 to Trump and five to Rubio, but the RNC recorded all 28 votes to Trump.
However, the appeal was unsuccessful because, RNC Chair Reince Priebus said, all the votes went to Trump because Rubio and Cruz suspended their campaigns.
Alabama Senator Jeff Sessions put Trump's name up for the nomination shortly before 6 p.m. The nomination was seconded by New York Representative Chris Collins, the first member of Congress to endorse him, NBC News added.
The former reality TV star was declared the "presumptive nominee" by RNC Chair Priebus on May 3 following his decisive victory in Indiana, which ultimately vanquished Cruz and Kasich from the primary and he entered the convention with 1,543 delegates.
The official nomination followed a rocky first day start of the RNC, the biggest backlash being Donald Trump's wife Melania speech being compared to the one Michelle Obama gave during the 2008 Democratic Convention.
Donald Trump is expected to formally accept the nomination during his prime-time speech on Thursday.