Be afraid, be very afraid. That sound of rumbling in the distance is not an approaching thunderstorm, nor the Led Zeppelin reunion concert, but hordes of Visigoths heading our way to plunder and pillage our peaceful cricketing way of life. If you listen carefully, the spluttering of be-coated and be-tied members of the MCG, SCG, Adelaide Oval and other staid cricketing establishments can be heard amid the din.

Twenty20, the never-pause-for-breath, biff-bang-and-wallop version of the game that is to cricket what Happy Gilmore was to professional golf, is set to become a growing feature of the international cricket calendar. And with it, Twenty20 will bring a whole new “non-traditional” audience to the game, quite possibly wearing Led Zeppelin T-shirts and drinking Wild Turkey out of cans.

That is the only conclusion to be drawn from extraordinary events in Australia this week. On Tuesday night, in a stunning vote of approval for cricket’s newest format, the TV audience peaked at 2.1 million viewers for the match between Australia and New Zealand at the WACA. The game, naturally, was a sell-out. By contrast, last month’s Test match between Australia and Sri Lanka could only attract an average audience of 627,548 with Australia’s first innings out-rated by Judge Judy.

Since 2005, the three highest-rating cricket telecasts in Australia have all been Twenty20 matches. Indeed, the eighth most-watched program this year, only marginally behind the AFL Grand Final, Kath and Kim and the Australian Open men’s final, was, yep, the Twenty20 match between England and Australia at the start of the year. It attracted an audience of 2,306,000.

Ever since its introduction to Australia in January 2005, Twenty20 has struck a chord with the sporting public. The “House Full” sign went up at the WACA Ground in Perth on that Wednesday night for the first time in 24 years. For a match between Western Australia and Victoria.

The format has proved equally successful around the world. Crowds for domestic Twenty20 matches in Australia, England, Pakistan and South Africa have often dwarfed those for Test and one-day cricket. In June 2005, more than 30,000 spectators packed Lord’s for a match between Middlesex and Surrey and in January the following year, a record crowd of 38,000 filled The Gabba for Australia’s first Twenty20 international.

Unsure what to make of this phenomenon that has sprung up under their noses like a blind pimple, cricket authorities have desperately begun to search for ways to enliven Test cricket, which is closer than ever before to going the way of the dinosaur and the Kiwi. Yesterday, Cricket Australia chief executive James Sutherland announced his radical solution: day-night Test matches. He said cricket could grab a massive four-fold increase in television ratings by introducing such a change within the next decade.

Yet the powers-that-be have been slow to embrace the phenomenon, treating it as the sort of curiosity you might see in a freak show, such as the Amazing Bearded Lady or Zip the Pinhead.

In January 2006, Peter Young, Cricket Australia’s communications manager, said: “Obviously Twenty20 cricket has been great for the English county game but we’re not sure how that translates internationally. The international calendar is already quite full. Test cricket is enjoying a resurgence and one-day cricket is a success. We’re conscious of that and don’t want to upset that. We’re still dipping our toes in the water with Twenty20 cricket at this stage.”

Well, the Test cricket resurgence was very short-lived. The game, except for a few pockets of resistance such as those in Australia, is now on the verge of being totally stuffed.

This week, we have been getting a different tune from Mr Young, who said the ICC, the game’s governing body, was considering staging three international Twenty20 matches next year instead of two.

“We are keen to look at what we can do to have three matches in the future,” Young said.

“We are having a red-hot look at it for next year.”

So much for dipping a toe in the water.

So the evidence is in and the jury’s reached its verdict: the Twenty20 game is here to stay. The trick now for cricket authorities is to somehow find a way to harness its energy and convert that into a massive electro-shock treatment to revive the five-day game which spawned it.