Bangladesh captain Mashrafe Mortaza says a collective performance is slowly becoming a winning formula for his side that beat South Africa by 21 runs in their World Cup opener on Sunday.

He didn't call the win their biggest ever but he said the wholesomeness of the performance delighted him, and would give the team much confidence for their next game.

"This is the team we are," Mashrafe said. "We mostly win when everyone contributes. Once most of our players step up, there's a good possibility to win the matches. I think we have been lucky, and played so well. We played well in the 2007 World Cup, and did well in a few matches in the 2011 World Cup too.

"I don't think this is our best win in terms of individual wins, but it wasn't easy for us in these conditions. It is one of our best performances because we are away from home, and I loved the way we played today. We know that it won't happen every day but we will take this win any day."

Mashrafe, however, warned his team-mates and fans not to go overboard with their first win in the competition with eight games remaining.

"We don't want to be too excited," he said. "We just have two points so far, so we should just focus on our game. We have to beat big teams if we want to do well in this tournament.

"I think from now we should forget about today's game. We have to plan against New Zealand, and try to execute it properly. This win will give us confidence but more challenges await us especially for our batsmen."

Mashrafe that he was pleased to see the batsmen play aggressively, yet not take too many risks. Soumya Sarkar embodied the approach by hitting nine chanceless boundaries in his 30-ball 42, before Shakib Al Hasan and Mushfiqur Rahim struck fifties, and later Mahmudullah and Mosaddek Hossain blasted 60-odd runs in the last six overs.

"It looked good that the batsmen built the innings without taking risks. I think they told themselves that we don't need to take many risks to score quickly. I hope that they took this message, and will apply it in the middle in the coming games."

Mashrafe didn't discount luck from the equation either, saying that when Mehidy Hasan Miraz got one to turn into Faf du Plessis and got him bowled, he knew something was up for them.

"I am a believer in luck," he said. "Everyone plans but it doesn't always come off. Luck is a factor in these tournaments, if you want to do well. The delivery that got Faf du Plessis was the only ball that turned, so luck is very much a thing."