Indian-American multimillionaire biotech entrepreneur Vivek Ramaswamy's popularity rating and online fundraising have surged, a day after his impressive performance at the first Republican presidential primary debate.

According to the Ramaswamy campaign, the 38-year-old presidential aspirant raised more than USD 450,000, with an average donation of USD 38, in the first hour after the debate on Wednesday.

The entrepreneur-turned-politician was being hit hard by three of his top rivals – former New Jersey Governor Chris Christies, former Vice President Mike Pence and South Carolina Governor Nikki Haley.

"In Trump's absence, Ramaswamy drives the GOP debate," popular Axis reported on Thursday.

The first poll that came out after the debate said that 28 per cent of the 504 respondents said that Ramaswamy performed the best. He was followed by Florida Governor Ron DeSantis with 27 per cent, and Pence (13 per cent). Indian-American Haley received the vote of seven per cent.

According to Fox News, Ramaswamy was the most Google-searched GOP candidate for the first Republican presidential debate. He was followed by fellow Indian-American Haley.

Both the Indian-Americans were standing next to each other on the debate stage.

"Vivek Ramaswamy Grabs Spotlight at First Republican Primary Debate," reported The Wall Street Journal. Its editorial board in its editorial was critical of his foreign policy proposals and said this will not get him to the White House.

A second-generation Indian-American, Ramaswamy founded Roivant Sciences in 2014 and led the largest biotech IPOs of 2015 and 2016, eventually culminating in successful clinical trials in multiple disease areas that led to FDA-approved products, according to his bio.

"Vivek Ramaswamy, the political novice, grabbed the spotlight at Wednesday's prime-time GOP presidential debate, but there was little sign he or any other contender had found a new strategy for overtaking front-runner Donald Trump," the financial daily said.

"With unchecked confidence and insults, the biotech entrepreneur baited his rivals into skirmishes that dominated Republicans' first debate," wrote The New York Times. "He came in hot, slamming his rivals, smiling wide and showing little deference to the more experienced candidates on stage," the daily wrote.

NBC News described the first debate as "Vivek Ramaswamy Show".

"That's our top takeaway from last night's first GOP presidential debate, where the political newcomer Ramaswamy seized the mantle as Donald Trump's defender – but also bore the brunt of attacks from rivals on his inexperience and foreign-policy positions," the news channel reported.

According to it, Ramaswamy was attacked 11 times by his rivals during the debate. According to Messenger – a fast-growing online news portal – the debate resulted in the rise of Ramaswamy's popularity.

"Vivek Ramaswamy sparred with Mike Pence. He battled Chris Christie. And he picked a fight with Nikki Haley. The longshot candidate and entrepreneur dominated the debate stage on Wednesday night, using his outlier policy views to grab attention and stoke the outrage of his opponents. Ramaswamy also gave his rivals an opponent to attack without alienating Trump supporters or elevating the second-place DeSantis," it said.

Ramaswamy appeared confident after the debate and told reporters that soon only two candidates would be left in the race, him and former President Donald Trump. On the debate stage, he described Trump as one of the best presidents of the 21st century. "I was the clear winner of the night. But we are just getting started...My sense is that it landed very well. Pretty soon it'll be down to a two-horse race between Trump and myself," Ramaswamy told reporters.

Ramaswamy, the biotech investor is worth more than USD 950 million. His net worth was over USD 1 billion about a week ago, making him one of the 20 youngest billionaires in the country, before a downturn in the market pulled him just under the billion-dollar threshold, according to Forbes.

Still, he appears to be the second-wealthiest person competing in the Republican presidential primary, behind only former US President Donald Trump (whose net worth Forbes last pegged at USD 2.5 billion).