RORY McILROY believes the Masters "owes" him a green jacket to complete the career grand slam after setting up a mouthwatering battle with defending champion Jordan Spieth.
McIlroy could have won his first major title at Augusta National when he took a four-shot lead into the final round in 2011, only to collapse to a closing 80 to finish 10 shots behind the winner Charl Schwartzel.
The 26-year-old bounced back to win the US Open two months later and the US PGA title in 2012, meaning victory in the Open at Hoylake in 2014 left him needing victory in the Masters to join Gene Sarazen, Ben Hogan, Gary Player, Jack Nicklaus and Tiger Woods in having won all four majors.
"I sort of feel that Augusta owes me something and I have come with that attitude," McIlroy said after a second round of 71 in swirling winds left him just a shot behind Spieth, who struggled to a 74. "I have come here to get something that I should have had a long time ago.
"You need to be so focused and in control of your emotions here. It's about not getting fazed and mentally I have been good the last couple of days. I need to keep that going for the next two days."
McIlroy was eight shots behind Spieth after 11 holes as the world No 2 threatened to turn the tournament into a procession for the second year running in his quest to join Jack Nicklaus, Nick Faldo and Tiger Woods in making a successful title defence.
However, Spieth then four-putted the fifth and became noticeably annoyed at being timed for slow play around Amen Corner on his way to his worst score in 10 rounds as a professional.
McIlroy took full advantage with birdies on the 13th, 15th and 16th to put himself in a great position, but admits he needs to ignore who he is playing with and the significance of what he is trying to achieve.
"Look, I know it's a very big weekend for me. I know that," he said. "But when I'm out there on the golf course, I just have to be completely 100 per cent focused on the task at hand, and if I can do that and stay in the moment and be completely focused over every golf shot I hit from now until Sunday night, then hopefully everything will work out the way I want it to."
Despite his rollercoaster round, Spieth still became the first player in Masters history to hold the outright lead for six rounds in succession, but joked he would rather play with someone "less threatening" than McIlroy.
"We seem to both be on our games right now and focusing on this week. With a lot of players behind us there is potential for someone to shoot a few under (on Saturday) and move into the lead from outside the top 25.
"I don think either one of us will focus on each other, we'll focus on the course. Sure it's exciting to play with Rory, but we'll not think much more of it."
The top 32 players are separated by just six shots, with Sheffield's Danny Willett, Sergio Garcia and Shane Lowry just four off the lead despite rounds of 74, 75 and 76 respectively.
US Amateur champion Bryson DeChambeau was also on level par after a triple-bogey seven following two wild drives on the 18th, when a par would have made the 22-year-old the only player in the field to break 70 on day two.