|Suresh Raina rushes to celebrate as Yuvraj sinks to his knees after crashing the winning boundary [GALLO/GETTY]
Yuvraj Singh provided another masterclass as India ended Australia's remarkable 12-year reign with a five-wicket win to set up a Cricket World Cup semifinal clash with Pakistan.
The win sparked wild celebrations among the country's billion-plus cricket fans and some 48,000 in the stadium as they anticipated a mouthwatering clash between two of the sport's biggest rivals.
Australia captain Ricky Ponting ended what is likely to be his last World Cup with a blistering century, but got few congratulations from the home crowd who unsportingly booed him before his post-match interview.
Opting to bat first in Ahmedabad, four-times champions Australia rode skipper Ponting's 30th one-day international century to post 260-6, which seemed a strong total at the Sardar Patel Stadium's low, spinning track.
Co-hosts India used seven bowlers, with Yuvraj, Ravichandran Ashwin and Zaheer Khan claiming two wickets apiece.
When India took to the crease, Sachin Tendulkar with 53, Gautam Gambhir with 50 and Yuvraj with an unbeaten 57 overwhelmed the target with 14 balls to spare in a 74-run partnership with Suresh Raina.
S Watson b Ashwin 25
B Haddin c Raina b Yuvraj 53
R Ponting c Zaheer Khan b Ashwin 104
M Clarke c Zaheer Khan b Yuvraj 8
M Hussey b Zaheer Khan 3
C White c & b Zaheer Khan 12
D Hussey not out 38
M Johnson not out 6
Total: (for 6, 50 overs) 260
FoW: 1-40 2-110 3-140 4-150 5-190 6-245
V Sehwag c Hussey b Watson 15
S Tendulkar c Haddin b Tait 53
G Gambhir run out 50
V Kohli c Clarke b D Hussey 24
Yuvraj Singh not out 57
MS Dhoni c Clarke b Lee 7
S Raina not out 34
Total: (for 5; 47.4 overs) 261
FoW: 1-44 2-94 3-143 4-168 5-187
India had enjoyed a fluent start until Virender Sehwag 15 fluffed his pull shot off Shane Watson for just 15.
Tendulkar seemed to be cruising to his 100th international century but the otherwise erratic Shaun Tait managed to induce an edge that sailed into Haddin's gloves and a deathly silence descended at the stadium.
Gambhir had just reached his 24th fifty when he ran himself out after an almighty mix-up with Yuvraj, having survived two such comical communication breakdowns immediately before the dismissal.
And in a breakneck race to the line, Yuvraj sent the 1983 champions into the semis with a pounded four to the delight of a raucous crowd.
"Playing Australia was a high-pressure game," said Yuvraj.
"I knew if Suresh and I had a 30 or 40-run partnership we could see us through to the end.
"Maybe it was my fault with the run-out but I apologised to Gautam.
"I've gone through a tough time in the last year but I'm hitting the ball well down the ground. Ponting batted outstandingly and we needed partnerships which got us through."
Earlier, Ponting's 104 off 118 balls and Brad Haddin's 53 held up the Australia innings after opener Watson (25) fell in a sluggish start.
But Haddin played without inhibitions and was particularly harsh on Munaf Patel.
The Haddin-Ponting partnership had yielded 70 brisk runs when Yuvraj once again underlined his importance as a part-time bowler, dismissing Haddin and Michael Clarke.
Mike Hussey's stay was cut short by Zaheer Khan (2-53) but his brother David (38 not out) played a cameo in Ponting's company to keep the scoreboard ticking.
Australia gleaned 44 runs from their batting powerplay overs without losing any wicket and Ponting took a single off Ashwin to reach his fifth World Cup century before giving his wicket to the off-spinner in the penultimate over.
Ponting's 118-ball knock included seven fours and a six.
India will take on Pakistan in the March 30 semifinal in Mohali.