Two-time Open champion Padraig Harrington's lowest round in a major shot him into contention for another Claret Jug and he believes his experience could be a significant factor on the final day.
The Irishman carded a seven-under 65 to leap to 10 under and give him a realistic chance of capturing his fourth major as the championship heads for Monday finish.
His previous best single-round score was back-to-back 66s on the weekend to win the 2008 US PGA, having also made that score at the Open way back in 2001.
Harrington's first win in seven years came at March's Honda Classic, which also needed an extra day, but it is his memories of getting the job done on the final day of a major that he will be looking to use on Monday.
"I always wanted to shoot 65 on the Sunday of an Open - obviously there's another round to go tomorrow," he said.
"I'll be certainly telling myself that I know what I'm doing and I've done it before and I'll be using it to help myself for sure, having done it twice before.
"Clearly things were going well for me today but I didn't want to look up (to the scoreboard) and see somebody getting away and be disappointed.
"When things are going well you might as well just keep your head down and keep going.
"There's no point in looking around and getting distracted.
"I didn't look until I finished off on 18."
The 144th championship at St Andrews is shaping up to be one of the closest in a long time with the top of the leaderboard tightly packed.
Harrington said at least that offered a modicum of hope on Monday.
Open week produces mixed feelings for Harrington as a decade ago his father died and he pulled out of the event at St Andrews and last year coach Bob Torrance passed away.
However, Harrington is too professional to allow anything other than competing for the championship to affect him.
"I'm not going to try to get emotionally involved in any shape or form," he said.
Source: PA
