Green's 54-hole total of 15-under-par 195 missed the three-round tournament record at this event by a single stroke. Tobias Dier posted a 194 in 2002 en route to victory.
'Fifteen-under was my target,' said Green. 'I felt that if I got to 15 at the end of the day, that would be a nice target. I have to stay in the present moment. That keeps me focused.'
David Lynn fired a 5-under 65 to take sole possession of second place at 12-under-par 198.
Ryder Cup hopeful Paul McGinley, who holed the winning putt for Europe at the 2002 Ryder Cup at the Belfry, shot a 2-under 68 and is tied for third place with Andrew Marshall (65) and Andrew Raitt (71). The trio is knotted at 8-under-par 202.
Green, who began the third round Saturday with a three-shot lead over Raitt, played steady golf to start his round. He rattled off five routine pars, but found himself in a little trouble at the sixth. Green's 30-foot birdie try ran 7 feet past the hole, but his par putt fell into the center of the cup.
He kept with his strategy of hitting his approaches to the center of the green and made three more pars that way for a front-nine, even-par 35.
At the par-3 10th, Green missed the putting surface short and right. He pitched 5 feet from the hole, then ran home the par-saving putt to maintain a two-shot lead over Lynn.
Lynn drew one shot closer at the 13th when he rolled in a 12-foot birdie putt. Green holed another clutch par save, this time from 6 feet at the 11th, but red figures were around the corner.
At the par-5 12th, Green knocked his second 40 feet short of the flag. He lagged his eagle putt to tap-in range for his first birdie since the 18th hole on Friday.
He missed the putting surface long with a 9-iron at the par-3 13th, but chipped in for birdie from behind the green. That birdie gave him a three-shot lead over Lynn.
Lynn kicked in a short birdie putt at the par-5 closing hole to get within two, but Green had two holes to play. Green made par at the 17th, then found the short grass with his second at 18. His 35-foot eagle try stopped 2 feet from the hole to give Green his first 54-hole lead on the European Tour.
'I kept my rhythm going nicely,' said Green. 'I feel like I'm doing it pretty well. I take it a hole at a time. I'm nicely flying along and that's what I want to do again tomorrow.'
Green, an Australian lefthander, has not won on tour since the 1997 Dubai Desert Classic. He has registered a pair of runner-up finishes this season at the Open de France and European Open and is 16th on the Order of Merit.
Despite his success in 2004, Green would love to visit the winner's circle again.
'Too long,' said Green, referring to the seven-year gap since his last victory. 'It would be a very emotional experience. Another 67 or a 66 would be nice.'
Lynn flew out of the gate on Saturday with a birdie at two and a 35-footer for birdie at the third. He bogeyed the fourth for the second time in as many days, but came back with a pair of 5-foot birdie putts at five and six.
He tallied six pars around the turn before his birdie at the 13th. Lynn polished off his round with a birdie at 18 to get within striking distance of his first European Tour win.
Per Nyman (70) and Stephen Scahill (67) are tied for sixth place at minus-7, while Andrew Oldcorn (67) and Miles Tunnicliff (71) share eighth at 6-under-par 204.
Ian Poulter, currently ninth on the European Ryder Cup points list, struggled to a 1-over-par 71 on Saturday and is alone in 10th place at 5-under-par 205.