Sri Lanka beat Afghanistan by 34 runs on the DLS method in a rain-affected clash in Cardiff.
Led by Kusal Perera’s hard-hitting 78, Sri Lanka waltzed to 144-1. However, a catastrophic collapse led to their dismissal for just 201.
Due to adverse weather, their Asian opponents were set a revised target of 187 in 41 overs.
They looked well on their way to sealing an historic first ever Cricket World Cup victory when needing 66 with five wickets in hand - having been reduced to 77-5 at one point - yet it ultimately proved too steep.
Nabi orchestrates Sri Lankan downfall
Openers Perera and Dimuth Karunaratne set about posing an imposing total during their time together at the crease, punishing some slack early Afghani bowling as they reached 92 without loss after 13 overs.
Sri Lankan captain Karunaratne then gave Mohammad Nabi his first victim, but after the loss of the left-hander for 30 Perera and Lahiru Thirimanne continued where the previous partnership had left off.
They were seemingly on their way to a challenging total with 144 on the board, and nine wickets and almost 29 overs remaining, however Nabi soon flipped the momentum of the game on its head.
The off-spinner snared the wickets of Thirimanne, Kusal Mendis and Angelo Mathews - the latter two both in their second deliveries faced - to disrupt the Sri Lankan's flow.
Kusal tried to support the tail but to no avail, as they lost their last nine wickets for just 57 runs, with only two of the last eight batsmen reaching double figures.
Furthermore, if it were not for the 35 extras conceded by Afghanistan then Karunaratne's men would have posted a severely embarrassing total.
Lower-order counter-attack not enough to see Afghanistan home
In today's game, 187 is a realistic score to be chased in 20 overs, let alone 41, and so the fact that Afghanistan failed to do so will be of major disappointment to those affiliated with the team.
A solid opening stand of 34 was compiled between Mohammad Shahzad (7) and Hazratullah Zazai which gave their side hope, as the pair batted well to give their teammates a platform from which to propel off.
However when Shahzad was dismissed by the excellent Lasith Malinga (3-39) this was the catalyst for the Afghan disintegration.
The succeeding four wickets were lost for the addition of only 23 runs, meaning that the restoration job was left in the hands of Gulbadin Naib (23) and Nadjibullah Zadran (43).
The pair dovetailed extremely well, as had been the case in their opening match against Australia when they put on 83 together, and utilised their differing qualities with bat in hand.
Captain Gulbadin nudged and nurdled, rotating the strike efficiently to ensure a steady accumulation of runs. As for the big-hitting Nadjibullah, he demonstrated a more relentless method of scoring as he smashed six boundaries during his time at the crease.
Their partnership was ended by the returning Nuwan Pradeed (4-31), who also accounted for the potentially-dangerous Rashid Khan for just two, two overs later.
When Nadjibullah was run out by a smart direct hit from Karunaratne the climb from then was too steep, with 42 required with only one wicket remaining.
The evergreen Malinga finished off the tail with his array of slower balls, dippers and yorkers, to ensure his side captured their first win of the competition.