Three wickets in the final over restricted Bangladesh to 150 for 7 after their allotted 20 overs against Zimbabwe in Sydney.
Shakib and Co bagged 87 runs in the last 10 overs.
Shanto top scored for the Tigers with 71 to his name while Shakib and Afif made useful 23 and 29 respectively.
For Zimbabwe, Richard Ngarava and Blessing Muzarabani bagged a brace each.
Shanto hit two 4s and a maximum of Evans in the 16th over to start the acceleration of Bangladesh's innings soon after reaching his fifty. But he could stay longer.
He was caught at mid-off for 71.
Afif is batting and he is joined by Mosaddek in the middle.
Bangladesh are 124/4.
Shakib Al Hasan and Najmul Hossain Shanto have built a 54-run partnership for the third wicket after the early wickets.
Shanto is batting on 47 as Shakib bagged 23 off 20 balls before departing.
Bangladesh are 87/3 after 13 overs.
Litton Das becomes Muzarabani's second victim in the sixth over.
The right-handed batter bagged 14 off 12 before getting out.
Shakib has now joinded Shanto in the middle.
Soumya Sarkar has departed for a duck early in the innings against Zimbabwe.
He was caught behind off Blessing Muzarabani in the second over of the innings.
Litton Das has joined Najmul Hossain Shanto in the middle.
Bangladesh are 24/1 after 4 overs.
Bangladesh have won the toss and have opted to bat first against Zimbabwe in a 'must-win' clash at The Gabba, Brisbane.
Both teams have made one change in their playing XI.
Yasir Ali comes in for Mehidy Hasan Miraz in Bangladesh's XI while Luke Jongwe sits out for Tendai Chatara for Zimbabwe.
"Looks a very dry wicket and we are always comfortable with runs on the board. Important game for both teams and we will have to play our best to win against Zimbabwe. They will be on a high after that win against Pakistan and we will have to play our best cricket," Shakib Al Hasan said at the toss.
Zimbabwe beat Pakistan in a thriller on Thursday and are currently sitting third in the Group 2 table.
Bangladesh were put to the sword by South Africa last time out, but have some in-form quality of their own.
Zimbabwe (Playing XI): Wesley Madhevere, Craig Ervine(c), Sean Williams, Sikandar Raza, Regis Chakabva(w), Milton Shumba, Ryan Burl, Tendai Chatara, Richard Ngarava, Brad Evans, Blessing Muzarabani
Bangladesh (Playing XI): Najmul Hossain Shanto, Soumya Sarkar, Litton Das, Shakib Al Hasan(c), Afif Hossain, Yasir Ali, Nurul Hasan(w), Mosaddek Hossain, Mustafizur Rahman, Hasan Mahmud, Taskin Ahmed