|Galgorm Resort & Spa Northern Ireland Open first-round leaderboard|
|-5 G King (Eng), R Santos (Por), N McCarthy (Eng); -4 M Nixon (Eng), M Schwab (Aut), T Murray (Eng), P Maddy (Eng), V Riu (Fra), D Huizing (Ned), T Linard (Fra), G Hurley (Ire); Selected others: -3 D McGrane (Ire), S Thornton (Ire), C Sharvin (NI); -2 M Hoey (NI), J Hood (NI) am, C Moriarity (Ire); Level C Koepka (USA), R Finch (Eng), R McGee (Ire), Jr Galbraith (NI); +1 C Selfridge (NI), G Moynihan (Irel); +2 D McElroy (NI); +3 R Davies (Wal); +6 O Wilson (Eng)|
English duo Gary King and Nick McCarthy and Portugal's Ricardo Santos share the lead at the Northern Ireland Open after opening five-under-par rounds of 66.
Santos and King both hit seven birdies at Galgorm Castle while McCarthy's round included an eagle at the ninth.
2013 champion Daan Huizing and Ireland's Gary Hurley are in a group sharing fourth after rounds of 67.
Ardglass man Cormac Sharvin shot a 68 while tournament ambassador Michael Hoey is a stroke further back.
After starting at the 10th, Sharvin's round included an eagle three at the 18th and birdies at the seventh and ninth.
Hood uses local knowledge to good effect
Galgorm Castle amateur Jordan Hood utilised his local knowledge superbly as he hit a 69 which left him sharing 24th spot in a group including Hoey, who is also the touring professional at Galgorm Castle.
Helped by an eagle on the ninth, five-times European Tour winner Hoey moved to three under after 10 but he dropped a shot at the short 14th before parring his way in.
Hoey's playing partner Chase Koepka, the brother of US Open champion Brooks Koepka, fired a two-birdie level par 71 which included a six at the long ninth after a lost ball.
Koepka is the leading player in the field in the Challenge Tour rankings, with him occupying ninth spot in the money list.
Knock amateur Colin Fairweather, who qualified for the event by winning the Northern Ireland Amateur Open at the Ballymena venue, is on course to make Friday's cut after shooting a one-under-par 70
Gavin Moynihan, the leading Irishman at the recent Irish Open, had to be content with a one-over 72 which was matched by Castledawson man Chris Selfridge, who dropped four shots in his opening six holes.
Portuguese man Santos, 34, is a European Tour winner having triumphed at the co-sanctioned 2012 Madeira Islands Open.
However, the Faro-born player has been playing mainly on the second-tier Challenge circuit since losing his Tour Card in 2014.
Santos is 24th in the Challenge Tour rankings and less than 7,000 Euro outside the top 15 spot which will guarantee promotion to the main circuit at season's end.
London-born King shared 14th place at the South Africa Open in January when Rory McIlroy was beaten in a play-off by Graeme Storm.
Since then King, 27, has missed eight successive cuts on the European Tour and he has opted to compete in a number of Challenge Tour events over the past two months.
The Englishman, who won Montecchia Open Challenge Tour event in ltaly last year, showed signs of better form when he shared 20th place at the Le Vaudreuil Challenge three weeks ago.
His compatriot McCarthy is playing only his second Challenge Tour event of the year having been given an invite.
This week's event has a new format with the top 24 players on Saturday evening going through to a final-day series of knockout six-hole stroke play matches.