Najibullah Zadran slammed a six off the second ball of the final over to give Afghanistan a six-wicket win against Zimbabwe on Saturday after a thrilling run chase in the first of three T20Is.

The dramatic climax seemed unlikely with 10 overs gone as the tourists scored 83 without loss after Zimbabwe posted 159-8 in 20 overs at Harare Sports Club.

Ryan Burl then wreaked havoc with the ball, capturing the wickets of openers Hazratullah Zazai (45) and Rahmanullah Gurbaz (33) and Usman Ghani (1) within six deliveries.

A leading edge from Gurbaz led to a catch for wicketkeeper Regis Chakabva. Zazai followed one ball later when caught by Sikandar Raza at long on.

Burl claimed his third wicket off the final ball of the over as another Chakabva catch ended Ghani's two-ball innings.

Batting at number five, Zadran stopped the rot but took time to regain the initiative and the tourists needed 60 runs from the final five overs to triumph.

The run rate gradually increased and when Blessing Muzurabani stepped up to bowl the final over, the Afghans required eight runs, and Zadran wasted no time getting them.

He hit two off the first delivery, then walloped his third six of a 25-ball stand to lift the Afghans to 160-4 and continue a successful tour after a 3-0 victory in a one-day international series.

Zadran, a 30-year-old left-hand batsman, struck two fours and three sixes in his unbeaten 41-minute stay at the crease.

Zimbabwe captain Craig Ervine told AFP it was a match the hosts could have won against opponents two places higher in the world T20 rankings at 10th.

"We started well with the bat -- Wessley (Madhevere) got us off to a good start. But we just had those little periods where we gave momentum back to Afghanistan."

Middle-order batsman Raza top scored with 45 for Zimbabwe on a hard, brown-grass, batting-friendly track.

Opener Madhevere (32) and Chakabva (29) were the other Zimbabweans to make significant contributions while six of their teammates failed to reach 10.

Debutant Najit Masood, a right-arm medium pacer, was the most impressive Afghan bowler taking three wickets, including those of Raza and Chakabva.

"It is the dream of every player to represent his country and to win their debut match. I bowled in good areas and that is how I took wickets," he said.

Pakistan-born Raza, whose T20 batting average is a modest 13.4, was out to a brilliant catch at third man by Hazratullah Zazai having faced 31 deliveries and struck three fours and two sixes.

A googly from Rashid Khan spelt the end of Madhevere while a leading edge from Chakabva was caught at mid-off by captain Mohammad Nabi.

The remaining two T20 internationals will also be in Harare, on Sunday and Tuesday.