Golf: Rory McIlroy, whose record-setting start produced the lowest 36-hole total in US Open history, kept up the pressure by going two-under on the front nine to boost his lead to eight shots in the third round.

McIlroy rolled in a 12-foot birdie putt at the fifth hole and tapped in for birdie at the par-five ninth in a bogey-free run to reach 13 under par at the 111th championship after beginning on 11-under-par 131.

A bogey followed at the 10th but he struck back at the 12th, the hardest hole on the course, to maintain his huge advantage.

The 22-year-old, nearly flawless from tee to green in posting rounds of 65 and 66 the first two days, was not so accurate off the tee at Congressional today yet saved himself with some precision iron play.

Surging into a tie for second on five under par were Lee Westwood and 23-year-old Jason Day, who both fired 65s to battle back from one over par after 36 holes. World number two Westwood used a birdie-birdie-birdie-eagle stretch from the 13th, while Day made six birdies after parring his first five holes.

"Big leads are sometimes difficult to play with," Westwood said after his round. "You just have to play your own game. I'm pleased with the way the day went."

Tied on four-under were Fredrik Jacobson, who registered a 66, Robert Garrigus, through 10 holes, and YE Yang.

Yang, who began the day alone in second place on five under par, bogeyed the second hole after a week greenside bunker shot and parred the rest of the way reach the 12th in four-under.

McIlroy was chasing his first major title, determined to erase the memory of a final-round collapse two months ago at the Masters when he surrendered a four-shot lead by shooting 80.

Westwood produced an astonishing charge today in an attempt to give his stablemate something to think about. Congressional’s back nine is rated much the harder of the two, but after a hat-trick of birdies from the 13th Westwood then rolled home a 20-foot putt for eagle at the 570-yard next.

Suddenly, having been down in 84th spot after his opening 75, the world number two — also chasing his first major title after a string of near-misses — was in second place.

Two closing pars meant a joint best-of-the-week 65 and a five under aggregate of 208. That was the good news. The bad was that McIlroy was still eight clear.