Tiger Woods and his son Charlie blamed poor putting as they had a disappointing first round at the PNC Championship.

The golfing icon and his 14-year-old son finished the day seven shots off the lead after carding an eight-under-par 64 in the scramble format, while leaders Matt Kuchar and his son Cameron made an eagle and 13 birdies in their round of 57. 

"I drove the ball really good today," Charlie Woods said.

"Didn't miss a fairway and still managed to shoot eight under. We just suck at putting."

"That sums it up right there," added Tiger Woods, who also had his 16-year-old daughter Sam acting as his caddie.

"Sam was fantastic. This is the first time she's ever done this, so it couldn't have been any more special for all of us.

"For me to have both my kids inside the ropes like this and participating and playing and being part of the game of golf like this, it couldn't have been more special for me.

"I know that we do this a lot at home, needle each other and have a great time. But it was more special to do it in a tournament like this."