Local hope Rhys Davies and Northern Ireland's Graeme McDowell both went to the turn in just 30 strokes at The Celtic Manor Wales Open - and were fighting for the title after overnight leader Marcel Siem had an early quadruple bogey seven.
Siem, three ahead when he resumed, put two balls in the water on the short third and after seven holes had fallen six shots behind.
In contrast Davies sank an eight iron approach to the eighth for an eagle two during a run of eight under for eight holes around the turn.
It took him to 11 under, but McDowell birdied six of the first eight holes to reach 13 under.
Four behind in joint third place were English pair Luke Donald and Robert Rock, Donald the man who pipped Davies by a stroke in last week's Madrid Masters.
The day had already seen Marc Warren equal the day-old course record of 63 set by his fellow Scot Stephen Gallacher.
McDowell's seventh birdie came on the short tenth from eight feet and lifted him three clear, but that became one when Davies drove the green on the dog-leg 377 yard 15th and holed from 30 feet for his second eagle two.
Incredibly, he was ten under for the round and two more birdies would give him The European Tour's first ever 59.
Davies's bid for the 59 effectively ended when he found sand on the difficult 16th and bogeyed.
He missed a ten foot chance on the short next and had to settle for another par at the last, giving him a new course record 62 and a 12 under total.
McDowell, though, remained the likely winner at 15 under with four to play.