Scotland head coach Anna Signeul bemoaned her side's lack of physical strength as they were beaten 4-0 by Iceland in their Euro 2017 qualifier.
The Scots lost their 100% record in Group 1 while the visitors took over at the top following their win in Falkirk.
"I think they were very strong going forward and we talked about it before that now it was time to step up against these physical teams," said Signeul.
"Because we have had problems against Norway and against Sweden."
Hallbera Guony Gisladottir's curling free-kick deceived the Scots to find the net in the first half.
And, after half-time, Harpa Thorsteinsdottir, Gunnhilder Yrsa Jonsdottir and Margret Lara Vioarsdottir all scored headers in quick succession.
"I think we are all surprised at the scoreline," said Signeul. "I don't think it was a 4-0 scoreline.
"It just shows you that we have a little bit to go yet. It was not just one thing that went wrong.
"It was their physicality. In the first half, we couldn't really keep up with that or stand up to them.
"I think we corrected some things at half time and I think we played much better in the second half, but still we conceded three goals."
Scotland can reach the finals next summer in the Netherlands, with the eight group winners and six best runners-up qualifying automatically, while the two remaining second-placed teams will meet in a play-off.
With 15 points from six games, the Scots are in a good position, with away games to come against Belarus on Tuesday followed by Iceland in September.
Signeul admitted the result irked her and said it is vital her side put things right.
"I think the players feel like me," she said. "They want to go to Iceland tomorrow, because we are not this, we are not 4-0 bad against Iceland.
"There are a lot of things we need to improve. We need to believe in what we are doing."
Iceland, who have a game in hand, play host on Tuesday to Macedonia, who were hammered 9-0 on Friday by Slovenia, who lie six points behind Scotland in third.
There were 2,700 fans at the Falkirk Stadium hoping to see Scotland take a significant step towards qualifying for their first major finals.
"A good turnout, lots of people, fantastic night," said their Swedish coach. "Were we fazed by it, did we look a little bit nervous in the beginning? I don't know.
"We have to keep our heads high and stay positive.
"What really matters is Belarus on Tuesday and if we have this hanging on our back that is not going to help us.
"If we get three points then we are back in it again."