Mohammed Shami attempts to run Mohammad Rizwan out at Dubai Cricket Stadium on Sunday night. Reuters
Violence against Muslims was also reported after the emphatic 10-wicket win on Sunday, Pakistan's first against India at any World Cup.
The 31-year-old Shami became the main target after the defeat in Dubai, even though India captain Virat Kohli acknowledged that his side had been "outplayed."
Thousands of vitriolic messages were left on social media, including Shami's Instagram account, calling him a traitor and alleging he had taken money to throw the game.
But a host of Indian cricket legends, fans, and politicians also spoke out against the hate onslaught and urged support for him.
"The online attack on Mohammad Shami is shocking and we stand by him. He is a champion and anyone who wears the India cap has India in their hearts far more than any online mob," said former Test player Virender Sehwag.
"We support every person who represents Team India," said batting legend Sachin Tendulkar. Shami "is a committed, world-class bowler. He had an off day like any other sportsperson can have."
Omar Abdullah, a former chief minister of the Muslim-majority region of Kashmir, called on Indian players to reject the hate messages just as they had backed the Black Lives Matter movement.
"Your BLM knee-taking counts for nothing if you can't stand up for your teammate who is being horribly abused and trolled," Abdullah said on Twitter.
"Ignore the haters, most of India's grateful for your effort," said another supporter on Instagram.
People set off celebratory gunfire in the Pakistani cities of Islamabad and Karachi after the famous win, while hundreds ignited firecrackers in Kashmir.
Gautam Gambhir, a former India Test cricketer who has become an MP for the ruling Hindu nationalist Bharatiya Janata Party, said it was "shameful" that people were celebrating Pakistan's win.
And in Punjab state students from Kashmir said they were beaten up.
A student at a technology institute in Sangrur said dozens of men armed with hockey sticks and batons attacked them as they watched the closing stages of the game.
"They entered our room, switched off the lights and beat us. They destroyed our laptops," the student told AFP, speaking on condition of anonymity because of fears of more trouble.
"We are safe now and we have support from our college. But we didn't expect this at all. We are Indians."
The match also sparked violence in neighbouring Bangladesh. Two Pakistan supporters were beaten by India fans as they celebrated the win in one southern district, media reports said.
Though Babar scored a half-century and Pakistan won the low-scoring warm-up game against the West Indies on Monday, the captain consumed 41 deliveries for his 50, while Rizwan struck his 13 off 17 balls and didn't score a single boundary.
Namibia reached the Twenty20 World Cup second round for the first time on Friday when they defeated Ireland by eight wickets.World number 19 Namibia, the lowest-ranked team in the tournament, chased down their modest target of 126 with skipper Gerhard Erasmus making an unbeaten 53.
Asif Ali stole the show with a quick-fire 12-ball 27 cameo after Haris Rauf took four for to help Pakistan set up a five-wicket victory against New Zealand in their T20 World Cup match at Sharjah Stadium on Tuesday.
"If Quinton De Kock wears pink for cancer or black arm bands to honour deceased greats or to oppose GBV when required, why object to a universally accepted gesture to fight racism?" he said. "But equally is it still a principled stand if it's mandatory?"
Angelo Mathews and Dinesh Chandimal hit centuries as Sri Lanka raised hope of winning the second Test after reducing Bangladesh to 34-4 on day four in Dhaka on Thursday.
Hosted by the Sharjah Cultural & Chess Club, the championship is being held under the patronage of His Highness Dr Sheikh Sultan Bin Muhammed Al Qasimi, Supreme Council Member and Ruler of Sharjah.
The 32-year-old, also a successful business professional and entrepreneur, finished 10th in the fourth round of the competition, earning him one point in the rally which attracted 48 teams in his category.