Sonia Bompastor questioned Chelsea's attitude and intensity after Saturday's 1-1 draw with Leicester City brought her perfect start to life with the Blues crashing to a halt.
Chelsea were looking to become the first team to start a Women's Super League campaign with 10 straight victories, with Bompastor already the first coach to win their first nine matches at the helm in the competition.
However, they were surprisingly held by Leicester, requiring a Wieke Kaptein equaliser after Missy Goodwin fired the Foxes ahead in the first half.
Chelsea were utterly dominant throughout, accumulating 28 shots and 1.9 expected goals (xG) to Leicester's two, worth 0.39 xG.
The Foxes had lost each of their last four WSL matches without scoring, but Saturday's result ensured they avoided becoming just the sixth team to lose five in a row to nil in the competition, after Yeovil Town (12), Bristol City (seven), Birmingham City (six), Doncaster (five) and Reading (five).
Bompastor credited Chelsea's hosts for their resilience but said she was disappointed with her team's start to the game, as just six of their shots came prior to the interval.
"For sure we're frustrated about the performance today," Bompastor said. 'When we talk about ambitions, we need to turn words into actions.
"I need my players to be ready from the beginning of the game. If you analyse this game, the first half was not intense enough from us.
"We did not show our intentions, and I think we got punished for that. The second half was better – we created more chances and opportunities – but we only scored one.
"We were not efficient enough to win this game. I'm frustrated because we have talent in the team, but we didn't show that in the first half.
"The players need to realise this is a competitive league and if you don't show up from the start, you don't get good results."
Chelsea's slip-up opens the door for Manchester City, who will now enter the winter break three points adrift of the summit if they overcome Everton on Sunday.
"It's even more frustrating for me because when the other team plays a really good game, you have to give credit to them," Bompastor continued.
"They were all together and mentally tough, but I think we have more talent than that.
"We had to be able to beat this team today and if you have ambitions to finish at the top of the table, you cannot drop points like we did in this game today."