There was a three-way tie at the top of the leaderboard after day one of the Irish Open, with South Africa's Dean Burmester and English duo Jordan Smith and Aaron Rai all carding five under rounds of 65 at the tricky Galgorm Castle Golf Club.

Play was suspended at the end of the day with just one group left to finish, but the trio were safe at the top, one stroke clear of Englishman Toby Tree heading into day two in Northern Ireland, where the performance of a homegrown amateur player set tongues wagging.

Irishman James Sugrue, the 2019 Amateur Champion who played at last week's US Open at Winged Foot, carded a three under 67 to sit just two shots off the pace - drawing comparisons with a famous amateur victory in this tournament by one Shane Lowry 11 years ago.

Lowry, returning to home soil for the first time as Open Champion this week, struggled to an opening five over 75 while European Ryder Cup Captain Padraig Harrington carded a one over 71 in his first competitive appearance in six months.

Burmester said he was happy with his efforts.

"I'm still cold. It's been a long time since I've woken up and hit balls in the dark too, but the greens were perfect and obviously it worked out for me today. I'm just happy to be back in the hut right now.

"For 16 holes I played flawless golf pretty much. I didn't really miss a shot. A couple of great up and downs kept the momentum going and then unfortunately on 17 I fell asleep over a three-footer but other than that, honestly I played great.

"I think if you'd asked me three days ago when I got here if I'd take 65, I would have taken it. It's a beast of a golf course and I hit it good off the tee and if you do that around here, you'll do good, so 65 in round one - anybody would be happy with that."

Other South Africans not far off the pace were Justin Harding and Garrick Higgo, who both shot two under par scores of 68, and Wilco Nienaber, who shot an even par 70.

Leading round scores from the first round of the European Tour's Irish Open in Ballymena on Thursday (GBR/IRL unless stated, par 70):

65 - Dean Burmester (RSA), Jordan Smith, Aaron Rai

66 - Toby Tree

67 - Stephen Gallacher, Rikard Karlberg (SWE), Oscar Lengdn (SWE), John Catlin (USA), James Sugrue

68 - Niklas Lemke (SWE), Justin Harding (RSA), Garrick Higgo (RSA), Lucas Bjerregaard (DEN), Martin Leth Simonsen (DEN), Scott Hend (AUS), Julien Guerrier (FRA), Jazz Janewattananond (THA)

69 - Marcus Armitage, Robert Rock, Scott Jamieson, David Law, Ignacio Elvira (ESP)

70 - Wade Ormsby (AUS), Jake McLeod (AUS), Maverick Antcliff (AUS), Clment Sordet (FRA), Wilco Nienaber (RSA), Fabrizio Zanotti (PAR), Joakim Lagergren (SWE), Damien McGrane, Daan Huizing (NED), Ewen Ferguson, Calum Hill, Jack Senior, Ben Stow, Graeme Storm, Oliver Farr

Selected others:

71 - Padraig Harrington

75 - Shane Lowry