South Africa U19 suffered a four-wicket defeat to Bangladesh U19 in the fourth match of the five-game one-day series in Rajshahi on Friday.

After losing the toss and being put in to bat, SA U19 slumped to 30-3 at the Shahid Kamruzzaman Stadium.

A partnership of 40 between opener Lhuan-dre Pretorius (50) and Richard Seletswane (18) followed, but that was as good as it got for the visitors.

Wickets tumbled rapidly around Pretorius as SA U19 were dismissed for 128 in 35.2 overs, with Rafiuzzaman Rafi bagging 5-18.

Left-arm spinner Liam Alder then took 3-45 to help reduce the hosts to 78-6, before Ashrafur Boronno (25*) and Mahfuzur Rabby (25*) held their nerve to secure victory.

The series will now be decided at the same venue on Monday.