|Bangladeshi Raqibul Hasan is bowled by Khan as his team slump to defeat [AFP]
Paceman Zaheer Khan ripped through Bangladesh's batting order to claim seven wickets in an innings for the first time in leading India to a crushing 10 wicket victory and a 2-0 series whitewash over the hosts in Dhaka.
Bangladesh had resumed on 228-3 but lost their last seven wickets for only 22 runs to be dismissed for 312 in the first over after the fourth day lunch interval, Zaheer capping a bowling masterclass to seal a maiden 10-wicket haul.
India, who had forged a 311-run first innings lead, got the two runs needed through leg byes off the second ball of their second innings, following up last week's 113-run first Test win with another comprehensive triumph.
"As the match went on, the pitch got slower and lower," Zaheer said.
"It was difficult to bowl on this wicket.
"There was nothing for the spinners, so was fast bowlers had a responsibility to put their hands up and take the wickets."
Zaheer triggered the collapse after spinners Pragyan Ojha and Harbhajan Singh ended the resistance of Mohammad Ashraful and nightwatchman Shahadat Hossain.
Ashraful and Shahadat added 62 runs in the morning to put India under a little bit of pressure before Ojha made the breakthrough.
Shahadat was the first batsman out for a career-best 40 as substitute fielder Amit Mishra held on to a catch at long-on, before Ashraful followed in the next over when he was caught by wicketkeeper Mahendra Singh Dhoni off Harbhajan for 25 runs.
Bangladesh first innings 233
India first innings 544-8 dec
Bangladesh second innings
T Iqbal c Dhoni b Zaheer 151
I Kayes c sub (Karthik) b Zaheer 5
Z Siddique c Dhoni b Zaheer 55
S Hossain c Sub (Mishra) b Harbhajan 40
M Ashraful c Dhoni b Ojha 25
R Hassan b Zaheer 5
S Hasan c Gambhir b Ojha 7
M Rahim not out 10
Mahmudullah c Vijay b Zaheer 0
S Islam b Zaheer 0
R Hossain b Zaheer 0
Total (all out; 90.3 overs) 312
Fall of wicket: 1-19 2-219 3-222 4-290 5-291 6-301 7-304 8-304 9-304
India second innings
V Sehwag not out 0
G Gambhir not out 0
Extras (b-2) 2
Total (no wicket, 0.2 over) 2
Shakib Al Hasan got off the mark with a straight six off Ojha before the bowler had his revenge in the next over, Gautam Gambhir taking the catch at square leg to remove the Bangladesh captain for seven.
Zaheer then took over for the visitors and ended any hopes Bangladesh had of setting a decent target with three wickets in the space of four balls.
In an exquisite display of reverse swing, Zaheer bowled Raqibul Hassan for five and completed his ninth five-wicket haul by removing Mahmudullah, who followed his unbeaten 96 in first innings with second-ball duck.
The left-arm pacer set up a hat-trick opportunity by uprooting the off-stump of Shafiul Islam with the next ball.
Rubel Hossain survived his first delivery and also helped ensure Bangladesh would avoid an innings defeat.
Mushfiqur Rahim (10 not out) struck Harbhajan for two boundaries in the next over to help Bangladesh wipe out India's first innings lead before Zaheer returned after lunch to take the final wicket and finish with figures of 7-87.
"It was quite slow yesterday and obviously they were taking their chance which went in their favour," Zaheer added.
"When we got two wickets towards the end of the day, we knew that we have the chance... and the ball was reverse swinging."