Sergio Conceicao kicked off his Nantes career with a win but immediately played down expectations of an instant revival at the struggling Ligue 1 club.
The 42-year-old former Vitoria Guimaraes boss, who took over from Rene Girard after a woeful start to the season, was speaking after the 3-1 win against Montpellier Herault SC in the Coupe de la Ligue on Tuesday.
While he was delighted with the win, and praised his players' determination and drive, Conceicao knows picking up points in the league will require a lot more work.
He told the Ligue 1 website: "I am really happy. We have won a match, but it is only one match.
"We had two days to work, gather information, work a bit on our defensive organisation, with confidence not exactly top, but the work we have done with the players was magnificent.
"These are things that with time we will improve, in terms of our organisation and also physically, because in the last 20 minutes our players were struggling.
"In terms of spirit and the ambition shown it was magnificent. It is encouraging for them because they have qualities and it is important to use each player's qualities for the service of the team."