Houston Open first round leaderboard

-5 A Tosti (Arg), R Gerard (US), K Mitchell (US), T Pendrith (Can); -4 T Mullinax (US), M Meissner (US), MW Lee (Aus), S Ryder (US), V Perez (Fra), R Hojgaard (Den), E Cole (US), J Suber (US)

Selected others: -3 S Scheffler (US), -2 H Hall (Eng), -1 D Willett (Eng), R Fowler (US), E R McIlroy (NI)

Northern Ireland's Rory McIlroy blamed a "pedestrian" start as he finished five shots off the lead after the first round of the Houston Open in Texas.

The world number two carded an opening-round 70, hitting two birdies and two bogeys at the Memorial Park course to leave him five strokes off early joint-leaders Keith Mitchell, Taylor Pendrith, Alejandro Tosti and Ryan Gerard.

McIlroy, who is hoping to complete a career Grand Slam by winning the Masters next month, opted to play in Houston for the first time since 2014 in preparation for Augusta.

"A little pedestrian I guess is a good way to describe it," McIlroy said.

"Made a few par saves early on that I needed to and then had quite a few chances on the second nine there that I didn't convert.

"Yeah, sort of tale of two halves. I felt like I was scrambling for the most part on the first nine and then I feel like I left a couple out there on the last nine."

Rain and wind made conditions difficult on the course while darkness forced play to be suspended at 7.28pm local time with a number of players unable to finish their round.

Scottie Scheffler, who is looking to defend his Masters title in Georgia in April, finished on three shots behind the leaders on two under.

The American hit a bogey-free opening round, recording three birdies along the way as he seeks his first win of the season.

"I felt like I started to play a little bit better on the back nine," Scheffler said.

"The first nine I was kind of getting it around a little bit but still post a score today.

"Conditions were pretty tough out there today with the rain and the wind so overall nice to keep a clean card."

England's Harry Hall posted a two-under 68 to finish three strokes off the lead while Danny Willett was four back.