HAMPSHIRE'S Justin Rose felt he had nothing to lose after scraping inside the cut on Friday and it freed him up to shoot the joint-lowest round in a Carnoustie Open.

The Englishman on Saturday posted his best 18-hole score in a major with a seven-under-par 64, with his previous lowest in the Open being a 66 20 years ago as an amateur on debut.

It was made possible only by the 13-foot birdie putt he holed on the 18th late the previous night which saw him move to three over and progress to the weekend.

He woke on day three to calm and warm conditions and a change in mentality saw him tear up the course, carding five birdies on the back nine to reach four under.

"I think the first couple days were hard work and frustrating," said the 37-year-old.

"But then there's a difference between being three-over on Friday and way off the lead and three-over and way off the lead on Saturday morning.

"You kind of feel a bit more grateful to be here rather than Friday night, you feel frustrated to be there.

"I think the birdie on 18 last night freed me up and I'm just very happy to be out on this golf course and not down the road somewhere else this morning.

"So that might have been part of the shift in mindset today. Obviously, I had nothing to lose from that point of view."

Coach Sean Foley departed last night but after all the tweaks and corrections they made this week Rose attributed his good round to the fact he played with more freedom.

"Basically, we worked on a lot this week, and I think sometimes you've got to let the dust settle a little bit," he added.

"I just kind of fell back into some sort of simple, old, reliable swing feels."

Despite his efforts in getting within two off the overnight leaders Zach Johnson and Kevin Kisne,r Rose is not getting too carried away with his position as he knows the course is there to be attacked today.

"I think that, if the conditions were to turn and it began to play much more difficult and they (later starters) realise that six or seven-under par is not really in the realm this afternoon it could lead to frustration more than pressure, I think," said the 2013 US Open champion.

"But no, I think at this stage it kind of shows them what's out there and gives them the intention that they need to look for birdies rather than play it safe.

"I thought four or five under was going to be a good round but nothing special, not going to do enough for me going into tomorrow.

"I felt like those late couple birdies certainly will make tomorrow at least interesting."