Ishikawa would be the youngest winner on the US PGA Tour in over 100 years if he triumphed while Day was bidding to become the second youngest winner of a World Golf Championships (WGC) event.
Asked if it made him feel old, Scott replied that he felt like a teenager himself, such was the crisp state of his game right now.
Despite dropping three back at one stage in his third round, Scott produced four birdies in his last seven holes to reclaim top spot.
"Being the old guy on top is not bad, to be honest. I'm just happy to be on the leaderboard, I don't care how old I am," Scott said.
"But it is amazing [to see so many young players performing]. Jason is playing well again and Ryo, it's unbelievable.
"I think golf is looking in good shape for the future really with players like this up here now."
Scott and Day finished tied second at the Masters and Day backed up with a runner-up finish at the US Open but Australia has had just one win on the US Tour this year - Aaron Baddeley's success at the Northern Trust Open in February.
The last time Australians had just one win in a season on the US Tour was 2002 when Craig Parry won this event.
"I think Aussie golf is in good shape," Scott said.
"For a while Geoff Ogilvy and I were leading the way there up in the world rankings and Jason is up there in the top 10 now. Richard Green nearly won again [in Europe] last week. We've got a lot of good golfers.
"And I feel like I'm moving in the right direction, and I think that'll probably pull a couple of other guys in the right direction also."
Scott was set to play in the final group with Ishikawa today, robbing Australian fans of an all-Aussie final group but he still expected a tough challenge from Day.
"I really like Jason's attitude," he said.
"He's out here and he means business. He's not out here to make friends is what I kind of feel like. He comes to the course and he wants it badly, and it's good to see, because he's not waiting for experience to just come along, he's out here getting it."
Despite his admiration for both Day and Ishikawa, Scott was ready to continue his impressive form when leading after three rounds. He has five wins from seven attempts when ahead after three rounds.
"I'm just going to look at it as a great opportunity," he said.
"My strategy is just to have a chance when I'm coming down the last."
- AAP
