But four birdies coming home dragged him back to one over, six behind the lead set by American trio Jordan Spieth, US Open champion Brooks Koepka and Matt Kuchar, and with the weather set to worsen on Friday the 28-year-old Northern Irishman is confident he can turn things around.
Kuchar had the better end of the draw with a morning tee time Friday. "We had a good time", Koepka said.
"It was just absolutely sheets of sideways rain is how I described it".
"I got off to a good start, which was important".
The 2015 champion endured a tough start on Thursday as he carded a five-over par 75.
Rory McIlroy declared himself "ecstatic" with a second-round 68 that put him firmly in contention heading into the weekend of The 146th Open.
U.S. golfer Zach Johnson, the 2015 Open champion, was the biggest mover of the day with a round of 66 being the best of the second round, taking him to joint-21 on one-over-par.
Aside from one round with his manager and another day for a photo shoot, Koepka did not pick up a golf club in the aftermath of his victory until arriving in England last Friday. "I feel like I'm right back in this golf tournament". Grace became the first player to shoot a 62 in major championship history, and also broke the Royal Birkdale course record by a stroke.
"For the R&A to give me that privilege at the first tee shot shows the respect for what they have for their Open champions, the respect to know that this was going to be my last Open Championship", he said.
With career earnings of more than $38 million, Kuchar is the highest-earning active PGA Tour player without a major championship.
After shooting a 69 on Thursday, Jason Day settled for a 76 in a wind-battered, rain-delayed 2nd round.
American Justin Thomas, sporting a black tie, matched Poulter's 67 to finish a shot ahead of world No. 2 Hideki Matsuyama of Japan, Sweden's Alex Noren and world No. 520 Stuart Manley of Wales. Golfers in a four-way tie for sixth at -1 and five back of Spieth include Austin Connelly, Rory McIlroy, Gary Woodland and Richard Bland.