David Gallop's "unstoppable" A-League appears under siege with the Big Bash League threatening to become a summer juggernaut if the first free-to-air TV ratings of the Twenty20 tournament are anything to go by.

Football Federation Australia boss Gallop last week pre-empted the start of the BBL season with a series of remarks casting doubt over whether sports fans would embrace the short-form tournament while claiming his own competition was "unstoppable in Australian sport".

But coming from a former first-grade fast bowler, those comments are beginning to look like pure spin.

Cricket Australia executives are delighted with the response from fans to the third season of the BBL as it appeared on free-to-air TV on the Ten Network for the first time.

Each prime-time match on Friday, Saturday and Sunday earned more than one million viewers across Australia in regional and metropolitan areas.

On Friday night, the only time the A-League and the BBL went head-to-head on free-to-air TV, the round ball code was well and truly hit for six.

The BBL's Melbourne derby between the Stars and the Renegades was watched by around 804,000 people in the five capital cities.

By contrast, the A-League clash between Brisbane Roar and Newcastle Jets was viewed by only around 74,000 on SBS2 according to the official OzTam ratings system; less than a tenth of the viewership of the BBL.

The BBL competition enjoyed only minimal lead-in coverage due to the Ashes battle and CA hopes the ratings will only get better.

"We're extremely pleased with the results from the opening weekend," the BBL boss Mike McKenna said in a statement.

"To break through the million-viewer barrier on Friday, Saturday and Sunday night with our first foray into prime time free-to-air TV is a terrific result.

"We still have a long way to go but the first four matches have set a strong platform for the rest of the season."

However Gallop can claim bragging rights in the battle for crowds in the southern capital.

The A-League Melbourne derby between the Heart and the Victory at AAMI Park on Saturday attracted a crowd of 26,491 while the Stars versus Renegades match at the MCG had a crowd of 25,266.

Quick Single: Full details on BBL's strong start