Australia's Warner stars in Afghan World Cup romp

David Warner hit an unbeaten half-century on his official return to international cricket on Saturday as Australia romped to victory by seven wickets in their World Cup opener against Afghanistan.

The five-time champions bowled Afghanistan out for 207 in 38.2 overs on a warm day in Bristol and then made steady progress, reaching their target with more than 15 overs to spare, with Warner 89 not out.

The match was the first official Australian appearance in any format for Warner and former captain Steve Smith since the end of their year-long bans for ball-tampering.

The crowd booed the pair and two fans watched the game from a balcony dressed as sandpaper after the scandal last year in which Australia hatched a plot to use the material to alter the condition of the ball.

"It's good to be back and it's a good win for us," said man-of-thee-match Warner at the presentation ceremony.

"There were nerves getting back into the camp and getting back into the full intensity of training, but to come out and bowl the way we did helped us set the tone with the bat.

"It's a positive victory and now we move onto the West Indies...There's a great buzz about this team at this moment."