Kayes continued his dazzling form in the series while Soumya made a comeback in style to put record 220 off 180 for the second wicket at Zahur Ahmed Chowdhury Stadium in Chattogram on Friday.
Mushfiqur Rahim made sure the Tigers do not lose the way with 28 off 39, finishing with a six when his side needed five runs to overhaul Zimbabwe’s 286 with 48 balls in hand.
In the chase of 287, the Tigers lost opener Liton Das in the very fast delivery of their innings, raising fears of a batting debacle.
Liton, whose 83 in a tremendous opening stand with Kayes earned Bangladesh a comfortable win in the second match, was trapped leg before by Kyle Jarvis.
The batsman challenged the decision in vain, slightly hurting his chances of getting a permanent spot in the team as Tamim Iqbal’s opening partner.
Soumya followed up after the 20th over, when Bangladesh’s score was 130, taking 63 quick runs in the next 10 overs.
He finally completed his comeback with 117 off 92, hitting nine boundaries and six sixes.
Selectors also breathed a sigh of relief as it was his second ODI century in his 35th match after the first one in the 10th in April 2015.
In the last match, Kayes achieved another landmark – he scored the most runs among Bangladeshi batsmen in a bilateral series.
His 115 off 112 with 10 fours and two sixes on Friday took his tally in the series to 349. Tamim had the record earlier with 312 in the series against Pakistan in 2015.
Earlier, Sean Williams emerged as the hero as he helped his team post their highest total of the series with an unbeaten career best 129 after they had lost openers Cephas Zhuwao and Hamilton Masakadza in the first three overs.
Mohammad Saifuddin and Abu Hider Rony’s inclusion in the playing eleven was proved the right decision as the youngsters shook Zimbabwe by taking the wickets of Zhuwao and Masakadza respectively.
The tourists failed to score a single run off 22 consecutive deliveries in the first five overs.
As the other pacers could not follow up on Saifuddin and Rony’s success, skipper Mashrafe Bin Mortaza brought Nazmul Islam Apu to the attack, but the spinner gave away 21 runs in his first three overs.
By the time he broke the 132-run partnership between Williams and Taylor, Zimbabwe were already on the front foot.
After Taylor threw away his wicket again sweeping Nazmul outside off and getting caught by wicketkeeper Mushfiqur, Sikandar Raza came to the crease. He immediately made his intentions clear with a six.
Raza’s 84-run stand with Williams took Zimbabwe past the 42nd over. Raza, who scored 49 in the second match, however, missed another half century, this time by 10 runs.
Trying to smash Nazmul for a maximum as overs were wearing out, Raza was caught at the boundary.
Zimbabwe, however, managed another partnership. Peter Moor hit two sixes in two consecutive deliveries by Mashrafe for his 28 off 21. His 62-run stand with Williams helped Zimbabwe throw a strong challenge, which Bangladesh overcame to complete their 12th ODI series sweep.