The volatile relationship between Australian cyclists Robbie McEwen and Graeme Brown fired up once more in a controversial opening to the Tour Down Under.

Brown, riding for the Italian Panaria team, crossed the line first in a fiercely contested bunch sprint finish to the 50km criterium through Adelaide.

But the Sydneysider was relegated to the back of the bunch for not holding his line and dangerous riding on the final sprint after arch rival McEwen, who finished in third place for the Belgian Lotto-Domo team, protested to chief commissaire John McDonnell.

The commissaire upheld the protest after studying tape of the finish, awarding the stage to another Australian - Baden Cooke - who crossed second for the French FDJeux.com team, and promoting McEwen to second.

After the decision was announced, Brown launched a broadside at McEwen, last year's stage winner.

"I can't run up the back of my lead-up man," said Brown, who won the stage in 2001.

"I've got to go somewhere and I think Robbie was stupid, a man of his class has gone up the left where there's one metre of room, where there's another 20 metres on the right hand side.

"I think he rode very stupid but ... I didn't win and he didn't win."

The drama followed an incident at the 2002 Bay Series when Brown was relegated from first to 11th in race two after McEwen complained about his tactics in the final sprint.

"I think that must be Robbie's easy option because that's twice now he's put a complaint in and the first time may have been a good complaint but this time I definitely think it wasn't," Brown said.

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