Nick Dougherty, one of two co-leaders after the first round, managed an even-par 72 and is tied for second place with David Howell (70), Bradley Dredge (68) and Pelle Edberg (68). The group is knotted at 4-under-par 140.
Heavy rain and high winds blew through the Colin Montgomerie-designed Carton House. The course has been called difficult by most in the field, so the combination of weather and narrow fairways made scoring very tough.
Dodd wasted little time in getting into red figures. He birdied the second hole, a hole he bogeyed on Thursday, but dropped shots at five and seven. Dodd closed his front nine with a birdie at the ninth to make the turn at even-par 36.
The Welshman made it two in a row with a birdie at the 10th, a hole he has birdied both rounds. Unfortunately, he bogeyed the 11th for the second time in as many days to fall to 3 under for the tournament.
The 38-year-old birdied the 13th and had a great look at birdie at the par-5 15th. Dodd's 4-foot birdie putt missed the hole, but he grabbed sole possession of the lead at Carton House's par-5 closing hole.
Dodd had a tree in his way for his second shot, but his third stopped six feet from the hole. He converted the birdie try to move clear of the logjam and grab the second-round lead.
Dodd has been enjoying the most success of his career in the 2005 season. He won the season-opening China Open, then tied for second at the Dubai Desert Classic.
All totaled, Dodd has four top-10s, including two in his last three starts. The success has translated into more confidence on the golf course.
'It's been a great six months obviously,' said Dodd. 'I had a good finish to the end of last season, and it gave me a lot of confidence. So did the start of this year, obviously, and I could not have asked for it to go any better.
'I just think I'm a lot more confident now about the way I approach things. I'm not saying I hit the ball any better because I probably don't. I think I do things in a more confident manner now.'
Dougherty opened on the back nine and bogeyed the 16th. He collected birdies at three and five to get to minus-5, but things went downhill thanks to an errant drive at seven. Dougherty bogeyed the hole to fall back into a tie for second.
'It's a very difficult course. On a day like today especially when it's windy and a bit wet, it's a beast of a course,' said Dougherty. 'Level-par today and 4 under yesterday is a great start.'
Howell also began on the second nine and bogeyed two of his first three holes. He parred his next seven until three birdies in a row from the second and a birdie at seven moved him into a share of second.
'Things are going well for me,' said Howell, who lost in a playoff last week to Thomas Bjorn at the Dunlop Masters. 'I know my game's in pretty good shape.'
Dredge mixed seven birdies and three bogeys for his 68, while Edberg tallied six birdies and two bogeys.
European Ryder Cupper Paul McGinley and Philip Golding each carded rounds of 3-under 69 and are tied for sixth place at 3-under-par 141.
Jose-Filipe Lima posted a 1-under 71 and is alone in eighth at minus-2.
Klas Eriksson shared the lead with Dougherty after the opening 18, but struggled to a 4-over 76. He joined Montgomerie and Lee Westwood in a group tied for 18th at even-par 144.
Defending champion Brett Rumford shot his second consecutive 73 and is tied for 39th at plus-2.
The 36-hole cut fell at 4-over-par 148 and Michael Campbell (149) and Graeme McDowell (149) failed to advance to the weekend.