Rory McIlroy carded a stunning bogey-free 65 to set the clubhouse target and open up a big lead on day two of the BMW PGA Championship.
The 2014 champion said after recording an opening 67 on day one of the season's first Rolex Series event that he was seeing positive signs in his game and so it proved in the second round.
Making his first appearance at Wentworth Club since 2015, the Northern Irishman made seven birdies in soft, overcast conditions but could have gone even lower thanks to a brilliant display of iron play that got him to 12 under.
Defending champion Alex Noren was five shots back after a 68 alongside Thai Kiradech Aphibarnrat and England's Robert Rock, with overnight leader Lucas Bjerregaard and Englishman Sam Horsfield also seven under still out on the course.
McIlroy looked dialled-in from the off and while he missed birdie chances from inside ten feet on the first, second and third, a birdie on the par five fourth after a lovely chip saw him make his first move of the day, with playing partner Noren also making a gain.
A Bjerregaard bogey on the first meant there was a four-way tie at the top and McIlroy had a near miss to take the outright lead on the fifth before saving par after finding sand off the tee on the next.
A stunning approach to four feet then handed McIlroy the outright lead at the seventh, with Dane Bjerregaard dropping another shot on the third.
Aphibarnrat held the lead late on Thursday but a seven-six finish slipped him back, and he sandwiched a bogey on the fifth with birdies on the fourth and sixth on the second morning.
The three-time European Tour winner was on a roller coaster, bogeying the seventh and then birdieing the eighth, while Bjerregaard took advantage of the par five fourth to get back within one of the lead.
McIlroy and Noren both put approaches inside ten feet on the ninth for birdies and Aphibranrat holed a ten-foot left-to-righter on the tenth to keep in touch.
Noren and McIlroy were going for blow-for-blow as they both got up and down for birdie on the par five 12th but when McIlroy holed a 25-foot left-to-righter on the 13th, he led by four.
Aphibarnrat also birdied the 12th before a 12-foot birdie from Bjerregaard cut the lead on the ninth but McIlroy put his tee-shot to tap-in range on the 14th.
Bjerregaard hit back with an excellent tee-shot of his own on the tenth but McIlroy made it four in a row from 35 feet on the 15th and he led by four again.
Rock then set the target as he turned in level par 34 but birdied the tenth, 12th, 17th - from long-range - and last to get to seven under.
Noren birdied the last to join him there and with Bjerregaard bogeying the 15th, Aphibarnrat was the nearest challenger thanks to a birdie on the 17th.
The 28 year old then put his ball in the water for the second consecutive day on the last to join the group five off the lead.
Bjerregaard had two holes to play, while Horsfield had three birdies and a bogey in his opening 12 holes.
South African Branden Grace and Northern Ireland's Graeme McDowell were in the clubhouse at six under, a shot clear of French duo Benjamin Hebert and Matthieu Pavon, and English pair Andy Sullivan and Lee Westwood.
Paul Waring made the fourth hole-in-one in three weeks and the 18th of the season on the European Tour when he holed his tee-shot on the par three fifth from 209 yards with a five iron.
