Moor Hall's Cameron Clark and Stoneleigh Deer Park's Matthew McGuire shot to the top of the leaderboard late on day one at the Ryder Cup Wales 2010 Welsh Open PGA Championship after carding level-par 69s.
The Midlands pair lead Oakdale's Matthew Griffiths and European Tour player Garry Houston, who both shot one-over-par 70s, by one shot, while three players - Paul Garnell, Simon Edwards and Lee Mackie - are two shots back on two over.
Six players, including Millbrook's Rob Brightman, are three over.
The wet, windy weather put paid to many players' chances at Royal St David's but the calmer conditions late on allowed Clark to take full advantage.
He fired back-to-back birdies on the last two holes to snatch a share of the lead, but admitted his six-hour-plus round had been tough.
"I hit it pretty well today," said Clark. "I hit the ball pretty solid all day.
"It was a real battle out there and I've never been on a golf course for so long in my life.
"Luckily the rain stopped on the back nine and the wind died down a lot towards the end.
"I didn't start that well with bogeys on three and five but I had an eagle on the eighth which got me going again.
"It was very satisfying to finish so well. I chipped in for birdie on the last which is always good to do.
"I holed a couple of decent putts too. The one for eagle was about 25ft. So yes, it's great going into tomorrow in the lead."
McGuire was even par on the front nine after two birdies cancelled out two bogeys, and bogey and a birdie on the way back in ensured he stayed level par.
"I played very steady," said McGuire, who was in the penultimate group to finish.
"It was difficult to get the ball close so thankfully the birdies went in with long putts.
"It took a long time. We are almost the last group to finish and it was getting pretty dark."
Griffiths was one of few players not to capitulate on the back nine and did not drop a shot after the turn. Two birdies made amends for three bogeys on the way out and put him in a good position going into day two.
"I'm very happy with my score," said Griffiths. "It is pretty gruelling out there.
"I just had a really good back nine and came back in in 31. I had twos on 11 and 18 and just ground it out in the bad weather.
"I had a top-10 finish last week so my form is good."
Griffiths insisted he is not getting carried away by his first-round lead, adding: "I'm in a nice position but you can't win it on the first day. You can lose it though, so I'm pleased going into tomorrow."
The highlight of the day was a hole in one from Sutton Green's Bernard White on the par-three 11th - his first as a professional.
"I knew when I hit it that it was a good shot and could be close," White said. "It was dead on line. Sometimes those ones end up not so good but thankfully this one rolled in."