Through 36 holes, the two sit on a total score of 9-under-par 135.
One shot back at 8-under are a trio of Swedes, in Robert Karlsson (68), Jarmo Sandelin (66) and Carl Pettersson (69), while two Scots, Andrew Coltart (68) and first-round leader Andrew Oldcorn (73) rest two off the pace at minus-seven.
As he did Thursday, Clarke opened with a flurry of birdies and appeared to be off and running from the get-go.
In the opening round, the big man from Northern Ireland made red numbers at each of his first six holes. Friday, he recorded six birdies over his opening 11 holes.
Yet, as he did on Thursday, he ran into a wall of sorts and could not sustain the excellent play. Bogeys on No. 12 and 17 brought him back to reality and 68.
I got off to a really good start, Clarke commented. I hit the ball well, hit lots of good shots and holed some nice putts. But the finish was disappointing. I thought I was on course for a 63 or 64 today. The mistake on the 12th cost me my momentum.
Unlike Clarke, Raitts success for the day came in the latter half. Playing the back nine first, the Englishman went out in even-par 36, but came home with six birdies against a pair of bogies for his 68.
While the story Friday was with the two leaders, perhaps the most excitement on the course came from the Karlsson/Sandelin/Pettersson group.
Between Sandelin and Karlsson, it was a festival of long putts all day, as Sandelin poured in birdies of 90, 50, 40 and 30 feet en route to his 66. Karlsson countered with a pair of 20-footers and a 40-foot bomb late in the day.
At just one off the pace, each man is hoping their luck with the flatstick will continue into the weekend.
'I have a short memory but I can't remember ever making so many long putts as this, exclaimed Sandelin. One out of 35 weeks in a season they go in like this. I'm hopeful it will stay for two more days now.'
We both played well, responded Karlsson. It was good fun.