Sixth and eighth places for Lance Stroll and Sebastian Vettel earned the team 12 points, the team’s best haul of the year.
The score moved Aston Martin from ninth place to seventh in the table, ahead of Haas and AlphaTauri. It is now only 15 points shy of sixth-placed Alfa Romeo.
However, Krack warned that the situation could change quickly should a bad weekend for Aston Martin coincide with a good double top 10 finish for one of its closest rivals.
“They're very valuable, because we jumped two places,” he said of the Singapore points. “But we need to be vigilant, because this can turn around quickly again. So we need to really keep focused, it's far from over the line.
“We always wanted to beat at least these two teams [Haas and AlphaTauri]. If we have one or two more races like this, then we can even look a bit further ahead. But I think we need to stay realistic, keep working hard and see where we end up.
“There are still five races to go. And there are still a couple of points to be gained. And a double DNF in Suzuka and a big score for others can mean that the situation goes the other way around again, so we really need to stay on it, and try to do it as well as possible.”
Krack was relieved that in Singapore, for once, Aston had a strong performance on a day that some frontrunners hit trouble - and was thus able to improve on its run of 10th places.
“In the end, the hard work pays off, and the consistent effort of trying to be there when it matters,” he said. “We have had a couple of occasions where we always get one point, two points.
“Today we were a bit luckier with attrition. But we were the ones that were there when it mattered, the drivers didn't put a foot wrong. And then it pays in such races.”
Krack believes that the team has found performance of late as upgrades have started to pay dividends.
“I think we've made progress since Zandvoort. We had another little update here. And we will have a small one next week [at Suzuka]. We identified the weaknesses of the car and steadily tried to eliminate them, which is good.
“Obviously, we came from a distance. But now I think you saw in Zandvoort that we were not so far anymore from Alpine and McLaren. And for us, the most important thing was to get ahead of this midfield group. And this we managed.”
Krack believes that the team can continue to improve its car even though only minor upgrades are still coming through the system.
“We had an update at Silverstone that took us one or two races to really understand how to make work, then we had a small tweak in France, which got us on the right path, I think.
“And then we understood more and more what we needed to work on. And that's why we now do what we can within the financial regulations; what is still possible to do.
“So it's a tweak here, it's a part there. Nothing major anymore. But I think it's very important that we keep going, trying to understand what the next step is to go faster.”
