Jordan Spieth spent the majority of his opening round challenging for the lead at the Vivint Houston Open. A back-nine collapse, however, sent him spiraling from T-1 to outside the top 90.

Spieth was 3 under par through 12 holes and in share of the lead at Memorial Park Golf Course. He then played his final six holes in 6 over par for a back-nine 40 and a 3-over 73.

"Well, [Nos.] 15, 16, 17 are where you can make some birdies, but you can also get into some trouble," Spieth said after his round. "So some risk-reward when you're attacking stuff or whether you are or not on."

Spieth's backslide began with a missed green and a bogey at the par-4 13th. He then failed to get up and down, for another bogey, at the par-4 14th. Spieth made double-bogey 5 at the par-3 15th, which played at 110 yards in Round 1. After missing the green left, Spieth's second shot ended up on the right side of the green. He pitched on from there and two-putted.

Following a par at the par-5 16th, Spieth made his second double bogey in three holes at the par-4 17th. Spieth's tee shot again traveled left and his second shot ended up in a water hazard. 

Spieth, who is winless on the PGA Tour since the 2017 Open Championship, averaged 317 yards off the tee on Thursday, but hit seven of 13 fairways and eight of 18 greens in regulation. He also lost more than 0.4 strokes on the greens.