Spieth made a 20-foot putt from just off the fringe on the final hole for a 6-under 64 and a share of the first-round lead Thursday in the rain-delayed Colonial.
"I had a few of those on the back nine, a few good looks where I knew what the putt was doing, I just didn't match the line and speed right," Spieth said. "I was getting a little frustrated through 17 there. I was like just one more look. … I didn't really count (18) as a look, but maybe more like luck, and we'll take it."
The closing birdie, just after 8 p.m., tied Spieth with
There was a huge roar at No. 1 when Spieth teed off in the first of consecutive events at home in North Texas since becoming a major champion. The Dallas player's approach at No. 18 landed just off the back right edge of the green surrounded by family, friends and plenty of fans.
"I was little frustrated to see where my ball went, but I was still was able to soak in kind of the welcoming to the 18th green," he said. "I'm sure it will continue to grow."
Spieth opened his bogey-free round with a 25-foot birdie putt at No. 1, then started the back nine with a 22-footer at No. 10. He had a great chance for another birdie on the par-3 16th, but a tricky 4-foot try slid by the hole.
Ishikawa, the 23-year-old from Japan, and 2013 Colonial champion Weekley also were without a bogey.
Na, whose only bogey came at No. 18 to close his first nine, curled up in a corner of the locker room and took a nap when tee times for the morning groups like his were pushed back three hours after more than an inch of rain fell overnight at Hogan's Alley.
"Pulled off a little veteran move, took about an hour nap," said Na, who grabbed a few extra towels, making one into a pillow, using another for a blanket and throwing another over his head. "So I felt great when I woke up."
Na originally woke up at 5 a.m. for a scheduled 7:22 a.m. tee time.