Boonchu Ruangkit tried kick-boxing as a young man but gave it up after being knocked out cold in his third bout.

Denis O’Sullivan put last week’s poor performance in Brunei behind him to notch six birdies in an opening round of three under par 69 in the Chang Thailand Senior Masters in Nakhonpathom.

It leaves O’Sullivan, who celebrated his 62nd birthday yesterday, comfortably insde the top 20, while Jimmy Heggarty had to be content with round of 71.

Both men find themselves chasing Boonchu Ruangkit, and not for the first time. Last week’s victor in Brunei is on home soil this week and leads the way again on eight under par after a sparkling round of 64.

Out among the early starters at the Royal Gems Golf Club, O’Sullivan didn’t take long to get himself under par, an opening birdie on the gentle par-five first was followed by another birdie at the third.

Bogeys at the fourth and sixth took the gloss off what had appeared to be a solid start, but the man from Cork picked up another shot at the ninth to turn in good shape.

On the inward nine, the joy of three consecutive birdies from the 12th was slightly tempered by the fact that they were immediately followed by a bogey at the 15th, but it all added up to a three under par total.

It was a slightly more frustrating day for Ulsterman Heggarty who, starting from the tenth, matched two birdies with two bogies on his opening nine before coming back in one under par to sign for a 71 

In the sweltering Thai heat it was Ruangkit who shot the round of the day, but it hadn’t looked quite so good after nine holes.

A solitary birdie had cancelled out an earlier bogey but as the home favourite pegged it up at the 10th he was level par and looking like ending the day well down the field.

Just 28 shots later Ruangkit had signed for an eight under par 64 and the clubhouse lead! The European Senior Tour’s in-form man made a mockery on the closing stretch, nailing six birdies and an eagle in the space of just nine holes.

The blistering finish gives Ruangkit a one shot lead overnight, with compatriot Manus Saengsui lying in second spot after his 65.

Of the star names in Thailand for the country’s debut on the European Senior Tour this week, Sandy Lyle carded a two under par 70 while Ian Woosnam and Sam Torrance fared no better than level par and plus one respectively.

Round One scores

64 B Ruangkit (Tha)
65 M Saengsui (Tha)
66 K Tomori (Jpn), J Chitprasong  (Tha)  
67 A Sowa (Arg), P Harrison (Eng), N Meesom (Tha), D Russell (Eng),
68 J Bruner (USA), S Ebihara (Jpn), M Williams (Zim), J Quiros (Esp), J Rhodes (Eng), B Lincoln (RSA), M Farry (Fra),
69 S Bennett (Eng), Denis O’Sullivan (Irl), L Yong-Gun (Kor), M Harwood (Aus), T Johnstone (Zim), M Cunning (USA), L Carbonetti (Arg), H Carbonetti (Arg),
70 S Lyle (Sco), J Rivero (Esp), G Brand (Eng), F Minoza (Phi), F Mann (Sco), D Merriman (Aus), G Gunn (Can), G Ryall (Eng), G Cali (Ita), K Spurgeon (Eng), B Cameron (Eng),
71 S Saengsui (Tha), C Rocca (Ita), M Ramayah (Mas), N Job (Eng),  R Chapman (Eng),  G Banister (Aus),  B Boyd (USA),  Jimmy Heggarty (Nir),  P Mitchell (Eng),  P Dahlberg (Swe),  S Bunpimuck (Tha), 
72 L Stephen (Aus),  J Chillas (Sco),  C Williams (RSA),  M Poxon (Eng),  S Owen (Nzl),  G Ralph (Eng),  B Hardwick (Can),  I Woosnam (Wal), 
73 B Longmuir (Sco),  T Gale (Aus),  S Torrance (Sco),  K Nam (Kor), 
74 P Teravainen (USA),  J Hall (Eng),  B Smit (RSA),  P Allan (Eng),  S Taylor (USA),  D Cambridge (Jam), 
75 N Ratcliffe (Aus),  M Miller (Sco),  M Piñero (Esp),  P Oakley (USA),  I Palmer (RSA),  A Garrido (Esp),  M Clayton (Aus),  A Tapie (USA), 
76 I Mosey (Eng),  J Hawkes (RSA),  T Chen (Tpe),  D Johnson (USA), 
77 A Johnsson  (Swe),  T Burgoyne (Sco), 
78 M Gray (Sco).