Great Britain edged past India 3-2 and assured themselves of a place in the final of an Olympic Games hockey qualifying tournament here.
Thursday night's result means that India, who have never missed the Olympic Games hockey tournament since 1928, are stuck at nine points and now need to beat lowly Chile Saturday to book a berth in Sunday's final.
In their last league match Saturday, if Austria, who have nine points, upset Great Britain (12 points) they will take their tally to 12. To avoid the second finalists being decided on goal difference - a scenario in which India are currently better placed - India will have no option but to beat Chile and qualify for the finals.
It was Great Britain's fourth win in the league phase and India's first defeat after wins over Russia, Austria and Mexico.
Only the tournament winner will qualify for the Beijing Olympic Games Aug 8-24.
In other matches, Austria defeated Mexico 3-1 after the two teams were locked 1-1 at half time and Russia edged past Chile 2-1 (half time 0-0).
Great Britain lead the points table with 12, followed by India and Austria, who have nine points each. Both Chile and Russia have three points each while Mexico are yet to open their account.
The India-Great Britain match started on an eventful note as India forced a penalty corner in the third minute and converted it to take a 1-0 lead.
Alistair McGregor in Britain's goal was completely wrong-footed by the tournament's leading scorer V.R. Raghunath whose powerful flick to the left sent the ball bang into the goal.
India were soon reduced to 10 men after Vickram Kanth was shown a yellow card even as Great Britain settled down following the early goal. They threatened the Indian defence but showed some nervousness in front of the goal.
Great Britain got the equaliser through a penalty corner by Richard Mantell in the 15th minute. The game was then confined to the midfield for a while with the traditional opposition of a more structured build-up from Great Britain and fast penetrating forays from India.
India were again reduced to 10 men when Shivendra Singh was shown a yellow card for a careless tackle. Great Britain controlled the game towards the end of the first half and came close to scoring.
India's Prabhjot Singh missed an opportunity to score when he got possession of a deep ball alone in front of the British goalkeeper but shot wide.
At half time, the teams were locked 1-1.
India, keen to avoid the embarrassment of missing the Olympic Games, attacked right from the word go in the second half with a series of penalty corners. But their opponents survived all of them.
Great Britain also forced a series of penalty corners but were unsuccessful in converting them. They finally took the lead in the 45th minute through Jonty Clarke, who was playing his 100th match. Clarke received the ball in front of an empty goal after a decisive penetrating run on the right by Ali Wilson and Richard Alexander.
India tried to create chances by hitting long balls into the opponents' circle, but the Great Britain defence thwarted all the attacks. India finally scored their second goal in the 64th minute when Raghunath struck again via a penalty corner.
This goal made him the top scorer of the tournament with eight strikes.
Great Britain regained the lead in the last minute of the game. Rob Moore, following another fast combination of passes in the striking circle, scored a field goal in the 69th minute.
Before the match started, India's Ignace Tirkey was recognised for his 200th international cap while Danish umpire Henrik Ehlers officiated in his 150th international.
Following are the positions of teams after Thursday's matches in the World Hockey Olympic qualifying tournament
(read under: Matches Played, Won, Drawn, Lost, Goals For, Goals Against, Goal Difference, Points): Great
Britain 4 4 0 0 26 3 +23 12
India 4 3 0 1 35 7 +28 9
Austria 4 3 1 0 15 15 0 9
Chile 4 1 0 3 9 10 -1 3
Russia 4 1 0 3 6 22 -16 3
Mexico 4 0 0 4 2 36 -34 0
(Points: Three for win, one for draw).