Virat Kohli smashed a century to steer India to 300 for seven against Pakistan in Sunday's World Cup blockbuster while South Africa staged a record-breaking recovery against Zimbabwe to claim a 62-run victory.
India's batsman Virat Kohli (C) plays a shot off Pakistan's spin bowler Shahif Afridi (R) as wicketkeeper Umar Akmal looks on, during their ICC Cricket World Cup Pool B match, at the Adelaide Oval, on February 15, 2015
Kohli hit 107, becoming the first Indian to make a World Cup century against his country's bitterest rivals, as Pakistan wilted in the 40-degree heat of the 47,000-capacity Adelaide Oval in a game being watched by a potential global audience of 2.5 billion.
But Pakistan stuck to their task and were indebted to seamer Sohail Khan who claimed five for 55 in his maximum 10 overs.
Tickets for the match, played out against a colourful background of noise, music and dancing, had sold out inside just 20 minutes in a powerful testament to the pulling power of one of the sport's highest-profile fixtures.
But it was India who were on top against an initially mediocre Pakistan attack as the defending champions looked to clinch a sixth World Cup win in six meetings against their neighbours.
Suresh Raina contributed a breezy 74 off 56 balls with three sixes while opener Shikhar Dhawan made 73 at just over a run-a-ball.
Giant paceman Mohammad Irfan, the tallest international cricketer at 7ft 1in, endured a torrid afternoon finishing with figures of none for 58 off 10 overs and getting warned for running on the wicket.
"We put a big total on the board and 300 is an important psychological number so we are really pleased with our batting effort," said Kohli after his 22nd ODI century.
"I tried to be patient and give myself more time so I could help the team to set up a big target. It's a two-paced wicket and it won't be easy to chase."
Meanwhile, traditional under-achievers South Africa got off to a disastrous start against Zimbabwe at Seddon Park in Hamilton before David Miller and JP Duminy staged a breathtaking rescue act.
From a precarious 83 for four, South Africa raced to a huge 339 for four with Miller smashing 138 for a debut World Cup century while Duminy scored 115 during the pair's unbroken stand of 256 -- a new fifth-wicket record in all one-day internationals.
The Proteas lost Quinton de Kock, Hashim Amla, Faf du Plessis and skipper AB de Villiers cheaply as their unheralded African neighbours threatened an upset.
But Miller, with seven fours and a World Cup record nine sixes, and Duminy, who hit nine boundaries and three sixes, took the game away from Zimbabwe in a stand which shattered the previous fifth-wicket ODI best of 226 between England's Eoin Morgan and Ravi Bopara against Ireland in Dublin in 2013.
Miller helped himself to 30 runs off the 48th over bowled by paceman Solomon Mire through three sixes and three fours.
"David was exceptional -- he just muscled it about all over the park," said Duminy.
Miller added: "We just kept encouraging each other along the way and we knew how important this partnership was to the team."
In reply, Zimbabwe were bowled out for 277 in the 49th over after Hamilton Masakadza (80) and opener Chamu Chibhabha (64) had briefly threatened an upset when they took their team to 191 for two.
Co-hosts Australia and New Zealand already have opening wins under their belts.
On Saturday, four-time champions Australia defeated England by 111 runs in front of almost 85,000 fans at the Melbourne Cricket Ground after New Zealand had comfortably seen off Sri Lanka by 98 runs in Christchurch.