SAB has begun a string of adverts directly attacking Anheuser Busch's Bud Light under the theme "the truth hurts". They show Bud Light drinkers startled to realise that Miller Lite tastes better.
"It continues to be very beneficial for us to periodically make direct comparisons with Bud Light based on the functional attributes of the beers," said Charlie Frenette, Miller interim chief marketing officer.
"Bud Light is a massive brand that is becoming increasingly vulnerable to consumer reconsideration."
The move comes after SAB admitted it was outmanoeuvred on price by A-B over the recent US Memorial Day Weekend. SAB increased prices by one per cent while A-B decided to drop its own by 0.2 per cent.
This, however, has led SAB to re-iterate its insinuation that A-B has acted irresponsibly by cutting prices in a troubled market.
"We said that we would not lead the discounting," said Doug Brodman, Miller's senior vice president for sales. "But we initially underestimated A-B's aggressiveness, and were not able to move quickly enough to address their cuts."
The firm said it stuck by comments made last year by chief executive Norman Adami. He said "results indicate that pricing is not the answer", and that the industry's long-term health depended on the major brewers devising good marketing behind their big brands.
The tension between brewers is unsurprising considering the continuing tightness of the US beer market. Overall, the big three brewers in the US - A-B, SAB and Molson Coors - are still struggling to gain momentum.
US domestic beer sales only rose by 0.5 per cent across the whole industry in 2004, according to the Brewers Association of America. And, A-B said its sales to wholesalers dropped 2.4 per cent in the first quarter of 2005.
Competition has reached feverpitch in the 'light' beers category because this is one of the only areas showing much promise. AC Nielsen recently named Miller Lite as the fastest growing beer brand in US supermarkets over the last year.
And market research group Datamonitor said that 'lite' and low-carb beers were giving the sector renewed strength. A study in 2003 revealed that about half of Americans were attempting to limit their carbohydrate intake.
Imports and craft beer continues to be the leading light of the industry. This segment edged up its market share at the same time as increasing prices by two per cent during the two weeks up to the Memorial Day Weekend.
A-B's Bud Select pulled the company out of a hole in the same period, offsetting declines in Bud Light and Budweiser. SAB market share dipped slightly after a poor performance by Miller Genuine Draft.
A-B has around a 50 per cent share of the US beer market. SAB, the market number two, has an 18 per cent share, while more than 1,300 craft brewers have a combined four per cent stake.