On Saturday against Burnley the gangly Dane's finishing prowess was distinctly Sunday morning pub league standard but on Tuesday it was worthy of the Champions League as his first Arsenal hat-trick helped power his side into the quarter-finals.
NEWS: Arsenal cruise into quarters
Bendtner, an industrial presence in a team full of artists, divides opinion at The Emirates like no other.
Willing worker though he is, he can on occasions look a little out of step with the silky movements of those around him.
He is an easy target for fans' when things are not going well but manager Arsene Wenger has always stood by him since spotting him playing for FC Copenhagen.
"It shows you how football can change very quickly," Wenger said of Bendtner after his side's 5-0 thrashing of the Portuguese that sealed a 6-2 aggregate win.
"It can go quickly up and quickly down. It shows that he had not lost his confidence and he came back with a good focus and belief, that's one of his strengths, his confidence levels remain relatively stable.
"He has the size and presence that we need because we are normally a very short team...he helps us offensively and defensively."
While Bendtner grabbed the match ball with two routine finishes and a stoppage time penalty, Wenger was quick to praise the impact of Samir Nasri and Andrei Arshavin whose pace and trickery tore Porto to pieces on the slick Emirates carpet.
Such was their impact that the absence of captain Cesc Fabregas went almost unnoticed while Nasri's exquisite solo dribble for Arsenal's third goal was sheer class.
"Nasri is developing very well," Wenger said. "What he showed tonight he shows in training and we expected that to come out in the games.
"He is a player with talent and he showed that tonight like he did on Saturday and he has started to be efficient now. Tonight he made the first goal and scored a great goal. Great players assist and score goals."
Arsenal's thumping win finally allowed them to overturn a first-leg deficit in Europe for the first time since they beat Hajduk Split on away goals in the 1978-79 season.
"The statistics were against us," Wenger said of the nine subsequent occasions that Arsenal had failed to recover from a first leg defeat. "But historical statistics don't mean a lot if you have a good team on the pitch."
