The Englishman slipped into full Ryder Cup mode, dramatically holing a 20-footer to enforce a play-off and then prevailing on the first extra hole.
The Englishman's Houston campaign had got off to a rocky start, having carded 75 on Thursday, however he more than found his form again after the fright.
"My tee-to-green stats have been fantastic", he said ahead of the WGC, "but my putting has to catch up, because if I get it back to where it was from 2009 to 2012 it will be very, very exciting".
End of Ramblers' run to remember
Series history: The schools have played three times before, but not since 1969, when Loyola won, 112-100, at Chicago Stadium. The Wolverines had a chance to tie, but Robinson came up way short on a triple in transition on the next possession.
"Poulter's victory was his third on the PGA Tour, with his previous two both coming at World Golf Championships events - the 2010 Match Play and the 2012 HSBC Champions in Shenzhen".
Jennifer Song dropped out with a par on the third playoff hole, and Park and Lindberg made a decision to take one more trip down the par-5 18th in fading light. Poulter, a five-times European team member, said his win would tell captain Thomas Bjorn: "Hey, I'm here, my game is in good shape".
Likely to move into the world's top 30 after a brilliant weekend, he is now in with a massive chance of making another Ryder Cup appearance in France later this year.
A stunning shot from the fairway bunker on the second hole earned Poulter his first gain of the day when he dialled in to six feet to take the outright lead on 15-under par before landing an approach to three feet for a tap-in birdie at the fourth to move two shots clear.
Malala Yousafzai ending 1st visit to Pakistan since shooting
In 2007, the militants had taken over the area, which Malala affectionately called "My Swat", and imposed a brutal, bloody rule. Yousafzai, who is now studying at Oxford University, visited the PM House and her hometown Swat during the visit.
Argentinian Grillo bogeyed the last to finish alongside three-time major championship victor Spieth at 16 under, with American Sam Ryder one shot further adrift.
Poulter followed an opening-round 73 that had him packing his bags in anticipation of a missed cut with rounds of 64 and 65 to reach 14-under 202 at the Golf Club of Houston.
"I had to dig deep today", said Poulter, who closed with a 5-under 67. "To come here this week, I was exhausted, frustrated on Thursday". I had packed my bags to leave on Friday night, and had a mental switch.
"I'm going to have a good day's rest tomorrow, I will not be venturing to Augusta until Tuesday".
Say it isn't snow! Springtime storm could bring more snow to tri
The temperature will be close to freezing, creating good conditions for snow - and not freezing rain - to form. Heaviest 24-hour snowfall events in New York City during April .
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