|Houston Open first-round leaderboard (US unless stated)|
|-8 S Ryder (after 15 holes); -7 L Glover, K Tway, B Hossler (after 16 holes); -6 R Armour, R Fowler, R Pampling (Aus), J Suri, P Dunne (Ire).|
|Selected others: -5 P Harrington (Ire), S Power (Ire), S Stricker; -4 J Spieth, H Stenson (Swe), P Mickelson, J Rose (Eng).|
Padraig Harrington's bid for a place at this year's Masters started well as he shot a bogey-free 67 in the Houston Open's weather-affected first round.
The Irishman has not competed in the Masters since 2015 but the winner of this event earns a place at Augusta.
He is two behind leaders Lucas Glover and Kevin Tway, although Sam Ryder is a further shot ahead but has only played 15 holes after rain delayed the start.
Jordan Spieth, Henrik Stenson, Justin Rose and Phil Mickelson are four under.
Rickie Fowler, who held the lead following an opening 64 last year before eventually finishing third, is on six under after seven birdies and a bogey.
Harrington's countryman Paul Dunne is also on that figure while another Irishman, Seamus Power, is on five under too.