In a post celebrating record downloads of his short video app Douyin， founder Zhang Yiming accused Tencent's messaging service WeChat of "plagiarising" Douyin's content.
Tencent's Pony Ma shot back that Mr Zhang's comments were "defamatory".
The two companies have gone further， filing competing lawsuits against each other over content and data.
Few outside of China may have heard of Mr Zhang or his company. But the group， with its 300m-plus monthly users， is the rare start-up with a shot at challenging the country's biggest tech companies.
The Douyin app was the most downloaded on Apple's iOS platform in China for the first three months of this year， according to QuestMobile， a research company.
But just as important， Douyin has not taken money from Tencent or Alibaba， two companies that have become Asia's biggest dealmakers through acquisitions of regional tech businesses and financial stakes in rising start-ups.
Unlike traditional investors， whose sole goal is typically to secure the best return， China's big tech groups are often looking to co-opt fast-rising services into their ecosystems in a zero-sum game to dominate the internet.
With its vast， youthful base of users， the platform is also an advertiser's dream and a potent force in ecommerce.
"Douyin's biggest selling point is its ability to make things go viral and that has a substantial influence directing traffic to ecommerce，" said Qu Kai， founder of tech investment consultancy Beijing Forty-two Chapters Technology.
Douyin and Bytedance have maintained their independence largely thanks to $2.8 billion of funding from global investors such as Sequoia and Susquehanna International Group.
"[Douyin] is the biggest in social right now and one of the few major platforms that's not owned or partially owned by Tencent or Alibaba，" said Ron Cao， a partner at venture capital firm Sky9 Capital and an investor in Bytedance.
The company also has its own messaging service， allowing it to bypass its bigger rivals' chat platforms.
Douyin's growing popularity has sparked a fierce competition with Tencent， which has its own popular streaming app and blocks most Douyin videos from its ubiquitous messaging app， WeChat.
Alibaba and Tencent have homed in on video streaming to pull users to their platforms.
China's top four short-video platforms had 582million users at the end of March， according to QuestMobile — equivalent to more than three-quarters of the country's mobile internet users.
This has implications for the Chinese online retail sector， a market valued at Rmb7.18 trillion ($1.1trillion) in 2017， according to the country's commerce ministry.