William Hill says its punters have been betting on table tennis since the coronavirus pandemic put paid to most conventional sporting events.
The bookmaker said the sport was part of its offer of "alternative products" for gamblers during the lockdown.
Other opportunities for wagers include football in emerging market countries not yet as badly affected by the virus.
Looking ahead, the firm said German football and French horseracing were its best potential earners.
Germany's Bundesliga is starting fixtures again behind closed doors this weekend, while racecourses had already resumed activities in France.
"While this is clearly an evolving situation, there are positive signs that some sports organisations are considering the resumption of live sports behind closed doors as early as this summer," William Hill said.
Countries where football has not been suspended include Belarus, which has seen its Premier League attract a new global following as a result.
The announcement came as William Hill unveiled a trading update covering the 17 weeks to 28 April.
It said that in the period to 10 March, before coronavirus curbs started to bite, its performance was "robust", although group revenues were down 5% year-on-year.
From 11 March onwards, however, its revenues fell 57%, because of the absence of live sports content.
William Hill said its betting shops were closed in the UK and US. UK retail staff have been furloughed and the bookmaker is topping up their wages to make sure they receive 100% of their salaries.
As it seeks to expand its US operations, William Hill has had to find innovative ways to get round restrictions on gambling in certain states.
In Nevada, people who wish to place bets using mobile phone apps have to sign up in person for the service at a betting shop before being allowed to use the app.
Since those facilities are currently closed, William Hill has set up temporary drive-thru services at several locations in Nevada.
Would-be punters have to download the app before heading for the drive-thru. To complete the registration process, they need to submit a picture of their state ID card and take a selfie with the app.