Schalke rounded off a superb week by taking another three Bundesliga points as they beat Nurnberg 1-0.
The club, who won at Arsenal in the Champions League in midweek, have made their best start to a domestic season since 1971-72, when they finished as runners-up to Bayern Munich.
And their Netherlands international striker Klaas-Jan Huntelaar believes they can only improve, saying: "We have the potential to get even better. We only look at ourselves, and we want to extend our winning streak.
"We've got a cup match against Sandhausen coming up next, and then Hoffenheim, who are not in top shape right now."
Schalke skipper Benedikt Howedes paid tribute to Peru international Jefferson Farfan, who hit the winner after 77 minutes. He said: "We bagged three points - that was our target. It was a hard-earned victory, but that doesn't matter. We kept in touch with the top of the table.
"It was hard to create opportunities in the second half, but thankfully we have Jefferson Farfan. He scored the golden goal. Jeff is a superb footballer with outstanding technique."
The victory put Schalke four points behind Bayern Munich. It is more than 50 years since the club last won the Bundesliga title - but they may be beginning to think this could be the year they end that drought.