The Fir Park men climbed back into the top six of the Scottish Premiership at the expense of the stunned champions who had appeared to be in cruise control.
Alexander watched the game from the directors’ box as he serves a Scottish FA suspension but was instrumental in the decision to send on Jordan Roberts, Liam Shaw and Justin Amaluzor at the start of the second half.
“We were in constant communication throughout the game anyway,” said Lucketti. “We spoke about how the first half went and what we would like to do in the second half.
"It was a decision the manager made to change the three players and the three players that came on had an instant impact.
“In the second half, they believed in themselves. We said at half-time about showing respect but not fear.
"Maybe in the first half, there was a little bit of fear from some of our players. We asked them to show belief in themselves - they are good players, they can handle the ball. They responded in the way that we wanted.
“We feel we have got a good squad and we felt we picked the right team, or a team that could come here and perform well. We have a lot of quality that didn't start the game and the lads that came off the bench added to that.”
After Roberts and Kaiyne Woolery scored to pull Motherwell level, the visitors had to defend desperately in the closing quarter of an hour to deny Rangers’ frantic efforts to secure a winner.
“When you come to places like this, against a fantastic team, they have a lot of possession and they do ask questions of you,” added Lucketti.
“You know if you are going to get anything out of the game you have to defend well. Certainly in the last 10-15 minutes there were all sorts of balls coming into our box.
" Every single player was putting their body on the line. It was a performance full of grit and steel for those last 15 minutes.”
Sixth placed ’Well, only separated from fourth spot on goal difference, continue their league campaign at home to Ross County this Wednesday night before hosting Dundee in the Premiership on Saturday.