Mobile esport games generated $15.3 billion revenue last year, according to a new 45-page report from Niko Partners.
Already accounting for 25% of mobile games revenue, the market intelligence firm predicted that mobile esport games will become the fastest growth sector in the esports industry.
The Evolution of Mobile Esports report suggests it will shift from spectator-focused tournaments toward more open regional tournaments.
"Mobile esports tournaments will engage consumers not only as spectators but as participants," said Niko Partners managing partner Lisa Hanson.
"This will create mass market participation and engagement, growing a far larger audience for esports and generating new opportunities for revenue.
"We will see esports transition from fewer large tournaments to the addition of large numbers of smaller tournaments that are open to everyone who wants to compete."
In terms of gross revenue, mobile esports games are already on track to outpace PC counterparts, which last year generated $16.1 billion revenue globally.
Overwhelmingly, China is the largest market for both mobile and PC esport games, accounting for $5.6 billion and $6.4 billion respectively.
According to Niko Partners, League of Legends remains the leading PC esport game, having grossed $1.9 billion last year -- down from $2.1 billion the year prior.
Despite being the leading esport, with record-breaking viewership figures every World Championship, Riot Games' MOBA actually drags behind Tencent's mobile title Arena of Valor, which grossed $2.5 billion in 2018 -- up from $2.4 billion in 2017.
However, there are four PC esport titles which generated over $1 billion last year, compared to just two in the mobile space.
For the record: This article has been amended for clarity to make a distinction between esport games, and esports.