STRIKER Lionel Messi starred for Argentina in their opening Olympic Games victory but only after his club Barcelona cleared him to play at the 11th hour.

The 21-year-old put the champions ahead and created another goal in the 2-1 win over the Ivory Coast.

In other matches, Ronaldinho played his first match in four months as Brazil beat Belgium 1-0 while Celtic midfielder Evander Sno was sent off in Holland's 0-0 draw with Nigeria.

Ronaldinho, who signed for AC Milan during the summer after a season of problems with injury and his fitness, was kept in check by the Belgian defence and restricted to two free-kicks.

"I haven't played an official football match for four months. I'm happy to return," said the Brazil captain, who has been included as an over-age player.

Meanwhile, after the fanfare of today's opening ceremony, tomorrow is a relatively low key affair, particularly for British hopes of medals.

Scotland's Caitlin McClatchey is first in action at the Water Cube, but only in heats.

But 400m legend Roger Black believes the British team have what it takes to better their Athens medal tally when they won 30 medals.

Black, a three-time Olympic medallist,said: "This Olympic team has had more money invested in it than any other.

"With that investment comes an expectation of more medals and I think we will achieve more medals than Athens."

In boxing, American bantamweight Gary Russell Jr. will miss the entire Olympics after collapsing while struggling to make his weight, US team coach Dan Campbell confirmed.

Lindsay Davenport withdrew from the singles at the Olympics today because of a lingering knee injury that has sidelined her since late June.

Davenport still hopes to play doubles with US team-mate Liezel Huber when the tournament begins on Sunday.