Harrington carded five birdies and an eagle on the par-5 18th against a pair of bogeys and tied first-round leader Poulter (68) at 7-under 133.
Harrington beat Tiger Woods with a birdie on the second hole of a playoff last year. Woods, who won the tournament in 2004 and 2005, is not taking part this year.
Finland's Mikko Ilonen also shot a 65 Friday and is one stroke back along with Japanese golfers Daisuke Maruyama (67) and Shingo Katayama (67).
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