Dustin Johnson goes for a knockout in the PGA Tour's final game, the Fedex Cup.

With 64 strokes, six under par and the best in the field's top tier, the American on Sunday extended his lead on East Lake outside Atlanta, Georgia.

"DJ" now leads with five strokes before the entire season's final lap.

- I get to go out and play as well tomorrow (Monday) as today.

I swing quite obviously well and I have plenty of confidence.

So I look forward to tomorrow, he says after his round.

After a Saturday where the game was not quite right, the knocks started to sit the next day, and with them came birdie after birdie.

Know what is required

In total, there were seven birdies, and only one bogey on the eleventh hole disturbed the fine score.

It came symptomatically enough after the rash ended up in the ruff.

The most impressive drive of the day came on the 18th hole, where he found the playing field with a 322 meter long shot - and a birdie as a reward.

- Today it felt completely different.

I met many more fairways.

I knew what it took to play well here and it's just to meet fairways, says Johnson.

Now he's just 18 holes from one of the few major trophies he's still missing in North America, a victory in the money-rich PGA Playoffs.

- To become Fedex champion is something I really want, says Johnson and looks forward to both a trophy and a victory check of 15 million dollars, around about 130 million kronor.

Hovland looks ahead

Closest behind Johnson are compatriots Xander Schauffele and Justin Thomas in shared second place.

But Schauffele does not believe anyone can threaten the leader.

- If he plays as he usually does, it will be virtually impossible to catch up with him.

Even if I were to put a birdie under the first three holes, he would not be shaken.

It is "DJ" we are talking about, he says.

Norwegian Viktor Hovland continues to play stably, but on Sunday had the margins against him and went around at minus two.

He is thus 21st, but his total of four strokes under par is only three strokes from a twelfth place.

- I had more chances today than I had the first few days, but I feel that I should have gone around in a couple of strokes less.

Now I will build on this and finish well, he says according to NTB.