Australia cruised into the final of the Under-19 World Cup with an easy six-wicket win over Afghanistan at Hagley Oval in Christchurch on Monday.

The three-time champions chased down Afghanistan's target of 182 at a canter, losing just four wickets as they reached it with more than 12 overs remaining.

Australian all-rounder Jonathan Merlo took four for 24 with the ball before opening batsman Jack Edwards smashed 72 in a player-of the-match knock.

They will play the winner of Tuesday's semifinal between India and Pakistan in the tournament decider on Saturday.

Afghanistan have had a dream run at this year's tournament, defeating Pakistan and Sri Lanka in the group stages, then thrashing hosts New Zealand by 202 runs to make the final four for the first time.

But their batsmen failed to fire against Australia, leaving a spin-heavy attack little to defend.

SCORES IN BRIEF

AFGHANISTAN U-19s: 181 all out in 48 overs. (Khil 80, Gurbaz 20; Merlo 4-24, Evans 2-26)

AUSTRALIA U-19s: 182 for 4 in 37.3 overs. (Edwards 72, Sangha 26, McSweeney 22 not out, Uppal 32 not out; Qais 2-35).

Result: Australia U-19s won by 6 wickets.

Player-of-the-match: Jack Edward.