Virgil van Dijk admitted Netherlands were out of sorts in Belarus after they relied on the brilliance of Georginio Wijnaldum to secure a narrow victory.
The 2-1 success in Minsk puts Netherlands on the brink of qualifying for Euro 2020, ending the team's recent exile from major tournament football.
After missing out on Euro 2016 and last year's World Cup, Netherlands finally appear to have got their act together under coach Ronald Koeman's leadership.
Van Dijk's Liverpool team-mate Wijnaldum scored both goals for the Dutch, heading in a clinical opener before thundering in a long-range strike to give the visitors a 2-0 half-time cushion.
Wijnaldum later said his second of the night was "by far the best" of the 15 goals he has netted for his country.
But Netherlands were shaky after the break, conceding when captain Van Dijk was at fault when allowing Stanislav Dragun to steal in for a close-range header, and then surviving several scares.
Central defender Van Dijk told Dutch broadcaster NOS: "The second half was, to put it mildly, not good. We lost the ball a lot in midfield after half-time, which allowed them to counter-attack. They weren't really dangerous, but we must do that better. We have to look at ourselves in the mirror.
"We all want to go to the European Championship. The whole of the Netherlands is yearning for that, including the players of course. We are close, but we have to analyse the second-half performance and then finish the job in the next international break."
Koeman's team face Northern Ireland and Estonia in their final two qualifiers in November, when it appears highly likely they will advance alongside Germany from Group C.
A point from their next match, against Northern Ireland in Belfast on November 16, would make sure of Netherlands' place in the 24-team finals. The Dutch beat Northern Ireland on Thursday, coming from behind to secure a crucial three points, and will be expected to avoid defeat at Windsor Park.
Despite concerns about the level of performance against Belarus, Van Dijk never thought Netherlands were in danger of losing their lead.
He said: "It might have seemed dangerous, but I thought we had it under control."
Wijnaldum echoed his skipper's verdict, saying, according to uefa.com: "We were complacent in the second half, and our positional play wasn't too good. We lost possession too often. We know we can do better. But it was a good result.
"My second goal was by far the best I've scored for the national side. We feel good, because six points from the last two matches is exactly what we wanted. But, of course, we remain critical.
"If we want to go far in the finals then we have to be at our best against the top teams in the continent."