January signing Semenyo has hit his stride quickly at City and looked like being a difference-maker in the title race after his winner at Leeds United on Saturday.
Against Forest, he scored his seventh goal since arriving from Bournemouth to give City a 1-0 advantage at half-time.
But a familiar story then unfolded. The statistics show City have dropped off in the second half of matches – had games finished at half-time, Guardiola’s side would sit 13 points clear of Arsenal but instead find themselves seven points adrift.
Forest had twice fallen behind but managed to hit back through Morgan Gibbs-White’s superb instinctive backheel and Elliot Anderson’s stunning curling effort.
The reaction from the City players at full-time was telling, heads bowed and shoulders slumped in the knowledge that these were two crucial points dropped.
“I would like to concede fewer but it’s not about analysing one specific action,” said Guardiola. “I never point fingers at my players. We did everything.
“We had the chances at the end and in the first half and the momentum. But something always happens and we could not win.”
Arsenal kicked off at the same time as City on Wednesday and capitalised by scraping a 1-0 victory at Brighton.
“Arsenal can keep playing badly and winning all they like – it’s the others that are faltering,” former England goalkeeper Rob Green said on Radio 5 Live.
“Manchester City are faltering and you just look at this Arsenal side and how they go about winning games, they manage to just grind out results and that’s all they’ve done tonight. They don’t care, they won.”
