New Zealand skipper Stephen Fleming conceded that Bangladesh had given them a "great, big headache" after his team's surprise two-wicket defeat in a warm-up game at Bridgetown last week.
Following their shock victory, Bangladesh have emerged serious challengers to the sport's big teams and neither India nor Sri Lanka can now afford to take Habibul Bashar's side lightly.
India may have won 13 of their 14 one-dayers against Bangladesh, but skipper Rahul Dravid has already said he expects each member of his team to be "switched on" for the crucial opening game in what is said to be 'group of death'.
Bangladesh's lone victory over India came at Dhaka in 2004.
"I expect the team to put up a very professional performance, irrespective of who we play against. We respect Bangladesh and we have seen what they have done against New Zealand," he said.
Batting holds the key to India's fortunes, with Sourav Ganguly, Sachin Tendulkar, Dravid and Yuvraj Singh all capable of demolishing any attack on any surface.
Hard-hitting opener Virender Sehwag may not have got a big score in recent matches, but Dravid said India had four batsmen -- Ganguly, Robin Uthappa, Tendulkar and Sehwag -- who had been opening the innings.
"If one or two guys are not doing well, then it is up to others to make up for it," he said.
Things have so far gone well for Bangladesh, who beat New Zealand and Scotland in practice matches. They need to beat either India or Sri Lanka to boost chances of making it to the next Super Eight stage.
First-timers Bermuda, the fourth side in the group, suffered a crushing 243-run defeat in their opening game against Sri Lanka here on Thursday.
Bangladesh's batting clicked in both the warm-up matches, with Bashar, Javed Omar, Tamim Iqbal and Saqibul Hasan all contributing to their team's wins.
Fast bowler Mashrafe Mortaza, and left-arm spinners Mohammad Rafique and Abdur Razzak are also in form, having played key roles in the practice games.
"We had a wonderful 2006 when we beat a few teams," Bangladesh captain Bashar said, referring to his side's eight wins in a row -- six against Zimbabwe and two against Scotland.
"We did not get to play big teams last year. Coming to World Cup we had a bit of worry since we had not played a big team for a while. But after beating New Zealand, we feel we can do it.
"India and Sri Lanka are contenders for the World Cup, so it's a big challenge for us."
Bangladesh coach Dav Whatmore, who led Sri Lanka to the 1996 world title, said his team could emerge as one of the surprise packets of the tournament if they played to their potential.
"If the boys are able to keep their focus and set about their task, and control what they can control, then we will be okay," he said.
India: Rahul Dravid (capt), Sachin Tendulkar, Sourav Ganguly, Robin Uthappa, Yuvraj Singh, Virender Sehwag, Dinesh Karthick, Mahendra Singh Dhoni (wk), Irfan Pathan, Ajit Agarkar, Anil Kumble, Harbhajan Singh, Zaheer Khan, Shanthakumaran Sreesanth and Munaf Patel. Coach: Greg Chappell.
Bangladesh: Habibul Bashar (capt), Shahriar Nafees, Tamim Iqbal, Aftab Ahmed, Saqibul Hasan, Mohammad Ashraful, Mushfiqur Rahim (wk), Mohammad Rafique, Abdur Razzak, Mashrafe Mortaza, Shahadat Hossain, Tapash Baisya, Syed Rasel, Rajin Saleh and Javed Omar. Coach: Dav Whatmore.