The score represented a new course record at the renovated K Club, as the course was lengthened over the winter in preparation for the 2006 Ryder Cup Matches.
Michael Campbell of New Zealand shot a 4-under 68 and is tied for third place with Argentina's Jorge Berendt and Sweden's Joakim Haeggman.
Two of golf's biggest names are part of a group tied for sixth place. Greg Norman, who won this tournament in 1986 before capturing the British Open later that year, opened with a 69 Thursday.
'If you drive the ball around here you are going to put yourself in a position to shoot a decent score and that is what I did today,' said Norman.
Colin Montgomerie, whose chances of playing this week looked doubtful because of a lingering back injury, also carded an opening-round 69 as the Scotsman looks for one of the titles that eluded him in his European Tour career.
'That is a good start,' said Montgomerie. 'This is one of the toughest courses we play all year on tour. It is a very demanding test of golf.'
Sebastien Delagrange, Barry Lane, John Dwyer, Chris Gane and European Ryder Cupper Niclas Fasth fill out the group two shots behind.
Fichardt got off to a rough start Thursday when he bogeyed the second hole but he rebounded with back-to-back birdies at three and four to get to 1-under. He nearly holed his tee shot at the par-3 eighth when his 7-iron hit the pin and bounded three feet from the hole, where he made birdie to make the turn at 2-under 33.
The South African birdied all three par-5s on the back nine at The K Club to get into the clubhouse at 5-under.
Fichardt won the Sao Paulo Brazil Open in 2001 and had a chance last week to add to his trophy case at the Irish Open. He was involved in a four-man playoff and missed a four-footer for the win on the first playoff hole. Soren Hansen captured the title on the fourth extra hole but Fichardt received words of encouragement from Mark McNulty, Thomas Bjorn and Retief Goosen.
'It hit me on Tuesday when I came to the course,' said Fichardt. 'But I got a lot of help from Mark, Thomas and spoke to Retief this morning and they said it happens to everyone. People do miss those putts and it could have been the first hole of the tournament or the playoff, it doesn't matter. The sooner I get up and back on the horse again the better.'
Moseley mixed two birdies and one bogey over his first nine, the back side at The K Club, but moved up the leaderboard on his second nine. He tallied four birdies over his last seven holes to match Fichardt at minus 5.
Moseley seemed to return to the form he displayed when he fired a final-round, course-record-matching 63 at the Volvo PGA Championship in late May.
'The season was very slow in starting but Wentworth kicked that off,' said Moseley, who won his first European Tour start at the 1999 Heineken Classic. 'I've really played well since then. I like a little break on the greens and these have more slopes and that suits me. I am enjoying getting better and if I can keep the progression going, then I will give myself chances to win.'
Darren Clarke, the 2001 European Open champion, struggled in the opening round of his title defense. He shot a 2-over-par 74 and is tied for 67th.
Full-field scores from the Smurfit European Open