South Africa rewrote the record books on Saturday as they posted the highest ever World Cup total of 428 while Aiden Markram clubbed the fastest tournament century in just 49 balls in a 102-run victory over Sri Lanka.
The Proteas bettered the previous World Cup high of 417 made by Australia against Afghanistan at Perth in 2015.
Their 428-5 was also the ninth highest total in all one-day internationals.
Markram, who went on to make 106, beat the previous record for fastest World Cup century which was claimed by Ireland's Kevin O'Brien off 50 balls against England at Bengaluru in 2011.
His first 50 on Saturday came from 34 balls while he needed only 15 more deliveries to add the next 50.
Rassie van der Dussen (108) and Quinton de Kock (100) also hit centuries in the first World Cup match to feature three tons in the same innings.
Kusal Mendis, Charith Asalanka and skipper Dasun Shanaka all then hit half-centuries but Sri Lanka's reply was always going to be damage limitation.
"It was a perfect day for us with the bat. We had to work hard up front up against the swinging ball and then well into the middle overs," said Van der Dussen.
"Aiden Markram when he plays like that is incredible to watch."
For Sri Lanka, the figures made for grim reading with two of their bowlers -- Matheesha Pathirana (1-95) and Kasun Rajitha (1-90) -- conceding more than 180 runs from 20 overs.
It was a remarkable display of big-hitting by a South African side who were skittled out for just 99 the last time they played at New Delhi's Arun Jaitley Stadium in October 2022.
De Kock, who is playing in his final international tournament, hit his 18th ODI century off 83 balls with 12 fours and three sixes.
De Kock put on 204 runs for the second wicket with Van der Dussen before being dismissed off the next ball he faced after reaching 100, top edging a delivery from Pathirana to Dhananjaya de Silva at mid-on.
- Sri Lanka battle -
Van der Dussen soon reached his fifth century in the format off 103 balls with 12 fours and three sixes.
The 34-year-old, playing in his 50th ODI, was out in the 38th over when Sadeera Samarawickrama took a catch on the long-on boundary.
De Kock and Van der Dussen came together at the fall of the first wicket when skipper Temba Bavuma was trapped lbw by Dilshan Madushanka for just eight in the second over.
Markram gave Sri Lanka no respite, racing to his half-century from 34 balls before he and Heinrich Klaasen (32) took the Proteas past the 350 mark in the 44th over.
Markram's century featured 14 fours and three sixes.
He plundered 18 off one over from Pathirana, the young, sling-action fast bowler hailed as the likely World Cup "X Factor" 24 hours earlier by Sri Lanka coach Chris Silverwood.
Markram was eventually dismissed when he skied the ball to Rajitha in the deep off Madushanka.
David Miller cracked 39 runs off 21 balls with two sixes in the late overs to further deepen the misery for Sri Lanka.
South Africa fast bowler Marco Jansen took two early wickets, clean bowling Sri Lanka openers Pathum Nissanka (0) and Kusal Perera (7).
Mendis, who hit 158 against Afghanistan in a warm-up last week, briefly threatened hope for Sri Lanka.
The 28-year-old raced to a half-century off just 25 balls but his resistance ended when Klaasen held on to a catch off a 140km/h delivery from Kagiso Rabada.
Mendis made 76 with four boundaries and eight sixes while Asalanka hit 79 with eight fours and four sixes.
Shanaka also helped restore a degree of dignity with 68, the first time in 14 innings he had got past 25.
Toss
Sri Lanka won the toss and chose to bowl first in their World Cup clash against South Africa at the Arun Jaitley Stadium on Saturday.
Both sides arrived in India with injury setbacks.
Sri Lanka, the 1996 champions, are missing leg-spinner Wanindu Hasaranga while off-break bowler Maheesh Theekshana is still unfit.
South Africa were stripped of fast bowlers Sisanda Malanga and Anrich Nortje.
The Proteas, who have never got beyond the semi-finals of the World Cup, named four fast bowlers in Kagiso Rabada, Lungi Ngidi, Marco Jansen and Gerald Coetzee with Keshav Maharaj taking on the main off-spinning role.
The last time they played in New Delhi in 2022, South Africa were bowled out for 99.
Matheesha Pathirana, described by coach Chris Silverwood as possessing the "X Factor" for the World Cup, starts for Sri Lanka with his distinctive slingy style.
Teams
South Africa: Quinton de Kock (wkt), Temba Bavuma (capt), Rassie van der Dussen, Aiden Markram, Heinrich Klaasen, David Miller, Marco Jansen, Gerald Coetzee, Keshav Maharaj, Kagiso Rabada, Lungi Ngidi
Sri Lanka: Pathum Nissanka, Kusal Perera, Kusal Mendis (wkt), Sadeera Samarawickrama, Charith Asalanka, Dhananjaya de Silva, Dasun Shanaka (capt),Dunith Wellalage, Kasun Rajitha, Dilshan Madushanka, Matheesha Pathirana
Umpires: Richard Illingworth (ENG) and Sharfuddoula (BAN)
TV Umpire: Michael Gough (ENG)
Match Referee: Javagal Srinath (IND)