With the five-match series levelled at 1-1, Yuvraj, who was dropped on 26 by Salman Butt in the 29th over, came up with a big score to notch up his 32nd half century and guide the hosts to a reasonable total on a batting pitch.
Put in to bat after Pakistan captain Shoaib Malik won the toss, India were saved from disaster as opener Sourav Ganguly was dropped on the first ball of the innings by wicket-keeper Kamran Akmal off pacer Shoaib Akhtar.
Akmal dropped a regulation catch off a full length delivery outside the off stump after Ganguly had a poke at the ball with the open face of the bat. The Bengal batsman, who opened his account with a single at third man two deliveries after Akmal's blunder, lived dangerously early in the innings being beaten by Akhtar and Umar Gul deliveries on a few occasions.
On the other hand, in form Sachin Tendulkar began from where he left at Mohali by hitting two successive fours off pacer Gul in the second over. He opened his account with a four to the fine leg and then caressed the ball to the fence with a sweet cover drive.
Ganguly was again lucky in the fourth over when he edged a Gul delivery to the vacant second slip for a boundary. Two overs later, Ganguly though came out of the shell and launched Gul for a six to long off.
Tendulkar continued his majestic form and he took India to 50 in the first ball of the eighth over finding the gap to the boundary with a square drive off Gul from a delivery outside the off stump.
He followed it up with a boundary past point.
Runs kept flowing and the same over, Ganguly added another four with sweetly-timed cover drive four.
After the 10th over, India were cruising to 67 for no loss with Ganguly and Tendulkar on 29 each and Pakistan putting pressure on the Indian opening duo taking the second power play in the 11th over.
The visitors got the result immediately with Tendulkar out on 29 in the 11th over off Tanvir. The master blaster was caught behind by Akmal off a full pitched delivery which he tried to guide to cover only to edge to Akmal for a fine catch to the dismay of full house crowd at 45,000 capacity stadium. Tendulkar hit five fours, facing 27 balls in his 54-minute stay at the crease.
When Tendulkar was out on team score of 68, he and Ganguly crossed a milestone for highest number of fifty-plus partnership for the first wicket. With today"s 68, the Indian duo had so far scored 44 fifty plus ODI partnerships for the first wicket surpassing Australian duo of Matthew Hayden and Adam Gilchrist"s 43.
Tendulkar and Ganguly had so far scored 6598 runs from 135 innings with 21 hundred plus partnerships and 23 fifty plus innings as compared to 5145 runs by Hayden and Gilchrist from 105 innings.
Ganguly got out in the first ball of the 15th over with Tanvir uprooting his off stump when he was out on 39 and team score on 82.
He faced 46 balls for his 39 and hit one six and four fours in his 79 minutes stay at the crease.
Yuvraj Singh, who came in at the fall of Ganguly"s wicket, opened account with a boundary off Tanvir from a ball drifting towards his legs and the Punjab batsman used his wrist to drive the ball past square leg boundary. Pakistan introduced Shahid Afridi in the 20th over at the end of which India reached hundred from the last ball. The over also saw Afridi and Gambhir in a confrontation after the two collided while the Delhi batsman was running for a single. A few uncharitable words were exchanged and umpire Ian Gould had to pacify the two players to calm down and fielding skipper Shoaib Malik was also called in.
Indian run rate dipped a bit in the middle overs with Pakistani slow bowlers operating and also lost their third wicket in the 28th over. Gambhir, who had a sedate innings today but looked settled for a long innings, was clean bowled by left arm spinner Abdur Rehman for 25 which the Delhi batsman scored from 49 balls with the help of one four. Gambhir was out at Indian team score of 129 but not before he and Yuvraj stitched 83-ball 47 for the third wicket.
Captain Dhoni came in and straightaway dispatch Rehman for a four from the second ball he faced.
After a lull of four overs without a boundary, Yuvraj brought the crowd to a frenzy in the 34th over with two sixes off Rehman.
He first hit a six to the mid-wicket fence and then two balls later drove over the long on boundary for a maximum result.
Dhoni joined his deputy and clobbered Malik for two sixes in the next over and the Indian duo scored 28 runs from two overs - 34th and 35th to wrest back the initiative. Dhoni then hit two fours in the 37th over off Afridi.
Yuvraj raced to his 32nd ODI fifty and seventh against Pakistan from 192 innings when he drove Afridi to deep square leg boundary.
This was his first fifty after ten innings. He had last scored a half century on September 2 against England.
Just as Dhoni was looking good for a big innings he was out just one short of his fifty bowled by an Akhtar slower delivery in the 44th over when the team score was 229. The Indian captain was outfoxed by the Pakistani speedster"s change of pace. Dhoni tried to drive a full length delivery to the cover only to find his off stump uprooted after the ball took the inside edge of the bat.
Dhoni"s 49 came from from 52 balls with the help of two sixes and four fours in his 60 minute stay at the crease. But this was after he and his deputy took the hosts to a good position by sharing 100 runs for the fourth wicket from 91 balls.
Yuvraj was finally out in the 47th off Rehman over trying to accelerate the score. The Punjab batsman attempted a sweep shot off a flighted delivery only to top-edged to Misbah at deep mid-wicket. His 77 came from 95 balls and was studded with four fours and six sixes.
Birthday boy Robin Uthappa did not last long and after hitting a lusty six and a four off Rehman he was out for 19 off the bowling of Gul in the 48th over. The Karnataka boy who turned 22 today hit one six and one four facing 17 balls.
Irfan Pathan and Harbhajan Singh then shared 29 runs from 16 balls to take India to 294 for six. Pathan struck two sweetly timed sixes in the penultimate over off Rehman to rakle 17 runs from it.
For Pakistan, Tanvir was the most impressive bowler taking two for just 26 from his ten overs. Left arm spinner Rehman also took two but conceded 58 from seven overs. Shoaib Akhtar chipped in with one for 40 from his 10 overs.
Earlier, India left out Virender Sehwag and opted for left-arm spinner Murali Kartik from the squad at Mohali in view of the flat pitch here. Pakistan also preferred Rehman in place of pacer Rao Iftikhar Anjum.