The twice former U.S. Open champion thrived on the slick greens at Firestone Country Club, shooting a three-under-par 67 in pursuit of a maiden victory in one of the elite World Golf Championships (WGC) events.
Goosen, who has consulted several back specialists since being troubled by two bulging disks, mixed six birdies with one bogey and a double-bogey to put himself in the hunt for a first PGA Tour victory in three years.
"I like this golf course," the 43-year-old told reporters after finishing one stroke off the early clubhouse lead. "For some reason I putt better on quicker greens. I feel I can make a better stroke when I just have to stroke it and not hit it.
"The greens are perfect here. If you hit it on the right line, it's good. But they're also very tricky. There's a lot of break on them, so it's hard to get the right lines, as well."
Asked to assess his overall health, Goosen replied: "About five out of 10. My physio is doing a good job keeping me on the course at the moment and I am in discussions with a number of doctors to see what options there are with the back.
"At the moment, we've just got to keep grinding away and play well. I am struggling to keep the muscles from firing down in the lower back. It's been a struggle for the last year."
Goosen, whose most recent PGA Tour victory came at the 2009 Transitions Championship, had to withdraw from the British Open and PGA Championship last season before taking a few months off towards the end of the year.
Though he returned to competition in November, December and January in South Africa, his back flared up in March and he has since had several protein and cortisone injections, along with extensive physiotherapy sessions, to help alleviate the pain.
"Some of the bone is growing a little bit funny so at the moment it is a struggle to sleep properly and to get going in the mornings, to warm up," he said.
"I'm losing a lot of distance out there on the golf course. I can't quite go at it as hard as I would like to."
Asked how he had been able to cope with the back pain, Goosen replied: "A lot of physio exercises. I'm working hard to try to get the inner core strong to support the back.
"I've had injections to take some of the nerve pain away. That's pretty much all you can do now, have physio, stay fit and try and stay as loose as you can."