• On Wednesday, BYD reported revenue for the three months ended Sept. 30 of 201.12 billion yuan ($28.24 billion), up 24% from a year ago.
• That exceeded Tesla's revenue of $25.18 billion reported for the same period.
• The milestone comes amid tough competition in China, the world's largest auto market, as well as higher tariffs on imports of Chinese EVs into the European Union.

Chinese electric vehicle maker BYD reported third-quarter revenue that topped that of behemoth rival Tesla for the first time.

On Wednesday, BYD reported revenue for the three months ended Sept. 30 of 201.12 billion yuan ($28.24 billion), up 24% from a year ago. That exceeded Tesla's revenue of $25.18 billion reported for the same period.

It's a first for the Beijing-based EV giant as its solid performance came despite the EV downtrend in mainland China. The company sold a record number of passenger vehicles in August.

At least half of BYD's sales are hybrid vehicles, whereas Tesla's vehicles are battery only.

But in terms of net profit, Tesla still took the lead.

The American carmaker saw net profit of $2.18 billion from July to September, up 16.2% from a year ago. Its Chinese counterpart, BYD, saw an increase in profit of 11.5% in the same period to 11.6 billion yuan.

Likewise, Tesla remains on top in year-to-date sales, slightly edging out BYD's roughly $70.53 billion total revenue at $71.98 billion.

BYD is one of the most prominent EV makers in China, the world's largest automotive market where it must contend with both domestic and global rivals for dominance.

On BYD's home turf, Elon Musk's Tesla is one of its toughest competitors. The Model Y remained the best-selling battery-powered electric car in China in September, according to Chinese automotive website Autohome. BYD's Seagull trailed closely behind in second place.

The competition will likely only get more cut-throat as European Union tariffs came into effect this week, despite China's disapproval.

On Wednesday, the EU announced it would implement tariff increases on Chinese EVs, taking duties to as high as 45.3%.

The extra tariffs range from 7.8% for Tesla to 35.3% for SAIC Motors, which will stack on top of a 10% standard import duty on all electric vehicles.

While tariffs imposed on BYD and Tesla were reduced from an earlier proposal, both automakers have taken steps to ramp up production in Europe which would help them work around the duties.

Reuters reported earlier this month that Tesla got the green light to double the capacity of its Berlin plant.

And BYD announced last year it would set up shop in Hungary. In July, the Chinese automaker said it would invest $1 billion into a plant in Turkey, which has a customs union with the EU.

— CNBC's Evelyn Cheng contributed to this report.