It was a fitting finish. Bismah Maroof skipped down the pitch at her opposite number, Stafaine Taylor, and drove a boundary through off the side to seal a clinical chase from Pakistan. They have had to bide their time to join the tournament as the last team to play a match, but their entry was one of the most complete performances so far.

Some context shows how significant the result was. This was their first T20I in Australia for five-and-a-half years; they lost their one official World Cup warm-up match that survived the weather in Brisbane by five runs to Bangladesh; they had only won two of their previous 12 T20Is against West Indies (although this win did make it two in a row after a victory a year ago in Karachi). Was this upset? The history would suggest so.

Pakistan have never moved out of the first round of T20 World Cup. Pre-tournament, when assessments were made about where sides stand, they were generally bracketed in the third tier - those aiming for, perhaps, a solitary win and a sign of progression. This performance suggested that they may be able to offer more than that. Pakistan are now one of four sides with two points in Group B and have Thailand to play. England and South Africa will pose tougher challenges, but they are on notice.

"We needed this win to move ahead," Maroof said. "I think looking ahead versus England, this win has given us some momentum and belief. The way this tournament has gone, it's quite wide open and any team can beat the other."

It all started with the first ball. Diana Baig won an lbw appeal against Hayley Matthews which pitched at least six inches outside leg stump (from a right-arm over bowler to a right-handed batter) but Matthews took too long to decide whether to review. There were some mystified looks in the West Indies dugout when she returned.

"Everything went wrong from the first ball of the game with Hayley getting out," allrounder Chinelle Henry said, aptly summing up West Indies' evening.

The wicket unsettled West Indies and Pakistan took advantage. Baig's opening spell was 3-0-6-2 as she also claimed the scalp of Lee-Ann Kirby when she carved a catch into the off side. Javeria Khan, who was named player of the match for her momentum-seizing 35 off 28 balls, believed the award should have been Baig's. "I am really surprised that I got this award. I think more than me, Diana [Baig] deserves it because she gave us the start which we never expected and I think she deserved it," she said at the presentation.

Deandra Dottin was clearly still struggling from the effects of the shoulder surgery that made her briefly ponder quitting the game - she can't throw in the outfield, relaying everything to a team-mate, and has yet to bowl - and laboured to 1 off 10 balls before picking out long-on in Nida Dar's first over. Then, as West Indies were staging a recovery through Taylor and Shemaine Campbelle, Maroof showed the value of getting a DRS call correct when Campbelle was initially given not out when she missed a reverse sweep.

There was a contrast to the energy in the two teams throughout. West Indies had scrapped together a total that could have challenged Pakistan with early wickets, but they were poor from the start in the field and by the time Khan and Muneeba Ali had added 58 for the first wicket, the game was Pakistan's to lose. The fact that never came close to happening emphasises how well controlled the chase was. There was a calmness about the batting, and a crispness to the strokeplay, that has not always been associated with Pakistan batting - one shot, a scything hit by Khan off Henry, stood out.

"We've struggled at times in the past, but we focused to stay calm and stay in the middle…and I think credit to Nida, as well, how she played and finished the game," Maroof said. "I think how the openers played set the tone for us, and we just needed to get the run rate going. We want to play aggressive cricket and get the bad balls to the boundaries."

When Maroof struck the winning boundary and ran up the pitch there was a little punch of the air. A job very well done. "Pakistan, Zindabad!" came the chant from a couple of small pockets of Pakistan supporters at Manuka Oval. Could this be their breakout tournament?