The Prime Ministers of India and Pakistan meet on Wednesday during a World Cup cricket match between the rivals, hoping to use one of the world's biggest sporting contests to rebuild relations shattered by the Mumbai attacks.
The two teams will meet in the northern Indian town of Mohali for a semi-final match. Scores of Pakistanis crossed one of the world's most militarised borders to travel to the stadium and millions of Indians have taken the day off work.
Prime Minister Manmohan Singh has invited his counterpart Yusuf Raza Gilani to watch the game and discuss reviving a peace process, although "cricket diplomacy" will offer more symbolic gestures than any breakthroughs in a conflict that has lasted for more than sixty years.
Bomb attacks in Mumbai in 2008 heightened distrust and complicated Western efforts to stabilise Afghanistan, where the foes are engaged in a proxy war. New Delhi blames Pakistani militants in collusion with elements of the government, including Pakistan's spy agency for the Mumbai assault.
Concerned about his legacy, 78-year-old Singh has pushed reconciliation with Pakistan despite misgivings within his own government.
In a major confidence-building measure ahead of the match, Islamabad agreed on Tuesday to let Indian investigators travel to Pakistan to probe the Mumbai bombings.
The two cricket-crazy South Asian nations have talked of little else for the past week in a buildup that has put the spotlight on, among other topics, players' preparedness, a row over match-fixing, and public prayers for victory.
Cricket is just one of the many cultural, religious and ethnic ties the two countries share dating back thousands of years. But the nuclear-armed rivals fought three wars and countless border skirmishes since their 1947 independence from Britain, feeding an obsessive mistrust.
Indian army helicopters and anti-aircraft guns have imposed a no-fly zone over the Mohali stadium, a few hours' drive east of the Pakistani border, to prevent an attack by militants.
Scores of Pakistani fans crossed the border post in India's northern Punjab state on Tuesday amid tight security.
"Obviously, love grows when two countries play together," said Syed Akbar Masood Nizami, a Pakistani cricket fan. "The people from both countries get together, sit together to cheer their teams and it helps develop feelings for each other."
Many companies in both countries have declared half days on Wednesday. The Karachi stock exchange plans to put a big screen up for traders to watch. Lawmakers in the eastern Indian state of Bihar have petitioned their government to suspend legislative business during match time.
"This is a more important event than any other event for Pakistan this year," said Omar Ehtisham Anwar, a fund manager at Faysal Asset Management in Karachi who has taken the day off to watch the match.
"There is no way I would miss even a second of this match -- I will try to not even blink during the game."
The winner of what has been dubbed the "mother of all matches" will play Sri Lanka in the final in Mumbai on Saturday.
Singh's political fortunes
For Prime Minister Singh, the match may be a way of regaining the policy initiative after his government has been battered by months of corruption scandals that could dent the ruling Congress party's chances in upcoming state elections.
Both sides will hope to ride a wave of goodwill ahead of talks between their foreign ministers in July, but some were skeptical about "cricket diplomacy", which was tried as long ago as far back as 1987, without bringing lasting peace.
"It facilitates resolution, it doesn't lead to resolution," former Pakistani President Pervez Musharraf told the Indian news channel Times Now. "Cricket diplomacy doesn't mean that you can resolve disputes just because you attended a match together."
Wednesday's game pits India's world-class players, including Sachin Tendulkar, against a Pakistani side that has looked in devastating form.
There was a sea of Indian fans' blue and red turbans in Mohali and the neighbouring city of Chandigarh which were patrolled by the local Punjab police, with some 1,500 policemen being deployed around the team hotel alone.
Police conducted surprise midnight checks on hotels near the stadium to verify the identity of guests.
Thousands who had travelled to Mohali to queue for tickets were left disappointed, but at dusk on Tuesday some die-hards decided to wait in line even after organisers had hung up the "sold out" sign. Some Indians reportedly decided to give up their tickets in a goodwill gesture to Pakistani fans.