Victory over the Proteas in the north-east will take Sri Lanka level on points with fourth-placed England, who are next in action on Sunday when they take on India.
India warmed up for that Edgbaston meeting by sweeping aside the West Indies, whose slim hopes of progressing to the knockout stages were extinguished following a 125-run defeat at Old Trafford.
Virat Kohli's fourth successive half-century underpinned India's total of 268 for seven, with Hardik Pandya and Mahendra Singh Dhoni injecting some late impetus as 81 runs were taken from the final nine overs.
The Windies succumbed to 143 all out after 34.2 overs under glorious blue skies in reply, with India all-but securing their semi-final spot as they moved up to second in the table.
One to watch
Lasith Malinga: The veteran slinger may not be able to match the speeds of the express pacemen at this tournament but his guile and inimitable action downed England in Sri Lanka's shock Headingley victory. The 35-year-old's figures of four for 43 included the crucial wickets of Jonny Bairstow, Joe Root and Jos Buttler. If Sri Lanka's charge for a semi-final berth is to gather momentum then Malinga will surely have to keep rising to the occasion.
Tweet of the day
India, who went to the top of the ICC one-day international rankings on Thursday morning, head into this Sunday's clash against England with their unbeaten record in tact. As against Afghanistan, India's batting was far from convincing but their pacemen and spinners made up for any shortfall to the delight of the sea of blue in the crowd.
Quote of the day
Jason Holder leaked nothing from his first 14 deliveries, bowling maidens at KL Rahul and then Kohli. Rahul blotted his copybook on the 15th ball Holder bowled with a drive back down the ground, but the West Indies captain had his revenge by castling the India opener through the gate with a nip-backer. Holder then snared Kohli en route to miserly figures of two for 33. Kemar Roach was equally impressive in taking three for 36.
Top of the shots
From his first 38 deliveries, Dhoni had amassed only 18 runs. This was not one of the countless instances where he finished at better than a run a ball but he did accelerate alongside Pandya, helping India to 81 runs in the final nine overs. Dhoni took two sixes and a four from the wayward Oshane Thomas in the last over of the innings. The best of the maximums was the first, a shorter ball sent into the stands beyond the deep midwicket boundary.
Today: South Africa v Sri Lanka at Chester-le-Street