Najibullah Zadran and Mohammad Nabi steered Afghanistan to a 21-run win over Zimbabwe on Sunday to claim a winning 2-0 lead in their Twenty20 international series in Harare.

The tourists won the toss and made 170-5 off 20 overs on a batting-friendly track while Zimbabwe scored 149-7 in reply.

A third and final T20 match is set for Tuesday with Afghanistan chasing a white-ball tour sweep after winning the one-day international series 3-0.

"The Zimbabweans batted very well, especially (Sikandar) Raza and (Innocent) Kaia. When Rashid Khan took Raza's wicket, that was the most important one for us as it changed the game," captain Nabi told AFP.

"(Bowler Najit Masood) has been brilliant for the last few years -- he is also playing very well in the domestic league and T20 league. He deserves to be in the national team."

Zimbabwe top scorer Kaia, who scored his maiden half century, was encouraged despite the loss.

"We bowled well today and used our powerplay well. We lost wickets here and there, but I think we were in the game.

"We just need to fine tune our middle-order batting -- we need to rotate the strike more and look for boundary options.

"I'm happy to score my first half century because I faced some of the best spinners in the world, like Rashid and Nabi.

"Those guys are Indian Premier League players, so for me I take it as a positive. I scored freely from their bowling so I think it is a positive."

- Quick, aggressive Nabi -

Zadran put on 70 runs for the fourth wicket with captain Nabi before he was run out off the first ball of the final over.

He carried on where he left off on Saturday, when his unbeaten 44 earned Afghanistan a six-wicket victory in a thrilling run chase.

His 57 on Sunday came off 46 balls and included six fours and one six. It was the seventh half century for the 30-year-old left-hander.

Captain and all-rounder Nabi was quicker and more aggressive than Zadran, averaging two runs a ball in an unbeaten knock of 43 that included a four and four sixes.

Opener Hazratullah Zazai scored 28, laced with three fours and two sixes, before he became the first of three victims of wicketkeeper Regis Chakabva.

Right-arm fast medium pacer Tendai Chatara was the most successful Zimbabwe bowler, capturing the wickets of Zazai and fellow opener Rahmanullah Gurbaz (1).

In reply, opener Kaia excelled, batting from the start of the innings to the second last ball before being run out on 54. His virtual run-a-ball innings included two fours and a six.

He was involved in profitable partnerships with Tadiwanashe Marumani (30) and Raza (41) that offered a glimmer of hope that Zimbabwe could win and level the series.

But they were always trailing on run rate and when Raza was clean bowled by Khan with 14 balls remaining and Zimbabwe on 136-4, a collapse ensued.

Rashid was the most successful bowler, taking 2-32 in four overs.