Bengaluru: India suffered early damage as Trent Johnston struck gold by sending off Virender Sehwag and Gautam Gambhir.
It was a leading edge that trapped Virender Sehwag at 5, chasing the meagre 208-target set by Ireland here at the M. Chinnaswamy Stadium.
Sachin Tendulkar and Gautam Gambhir were on damage control when Johnston came out with a bad ball to sent packing Gambhir.
Earlier. part-time spinner Yuvraj Singh bagged a maiden five-wicket haul as India dismissed Ireland for 207 in their World Cup match on Sunday despite skipper William Porterfield's half-century.
The left-arm spinner's victims included Kevin O'Brien (9), who hammered the fastest century in World Cup history in his team's upset victory over England, as Ireland lost their last eight wickets for 85 runs.
Yuvraj (5-31) gave the capacity crowd plenty to cheer about after left-arm paceman Zaheer Khan had rocked Ireland with two early wickets in the day-night match in Bengaluru. Zaheer finished with 3-30.
"Normally I'm a batsman so it's a satisfying feeling when I get runs but doing a job with the ball is a great feeling to get a five-for," said Yuvraj.
"We're a team and we're doing really well, playing well as a unit so we should get this score," he added.
Porterfield (75), dropped on nought by Yusuf Pathan in the slips off Zaheer, went on to complete an impressive half-century, his fifth in one-dayers, before being caught in the covers off Yuvraj. He hit one six and six fours.
Ireland were on course to post a challenging total following a 113-run stand for the third wicket between Porterfield and Niall O'Brien (46) before they slipped from a healthy 122-2.
They suffered a crucial blow when well-set Niall O'Brien was run out after completing 1,000 runs in one-day internationals. His brother, Kevin, failed to repeat his heroics from the last match as he offered a return catch to Yuvraj.
There was no hint of the slide when Porterfield and Niall O'Brien were steadying the innings after Zaheer's double strike.
The Irish pair never looked in trouble, comfortably gathering runs against both pace and spin. They initially relied on singles and twos before Porterfield swung leg-spinner Piyush Chawla over square-leg for a six.
Zaheer earlier struck with the fourth delivery of the match when he bowled Paul Stirling for a duck before having Ed Joyce caught behind for four.