First-half goals from Lionel Ainsworth and John Sutton left the Steelmen level on points with Aberdeen, who remain in second due to goal difference in the Scottish Premiership.
Inverness stayed in fifth place, without a win in their last five matches, but Hughes still has high hopes for the Scottish League Cup finalists.
"We need to get back to keeping clean-sheets - that's what we pride ourselves on," he said. "If we do that, with 10 games remaining, the challenge is to try to get Europe.
"To do that, we need to get back to winning football matches. By hook or by crook, we have to win a football match.
"I would never bet against those guys in that dressing room doing it. That's for sure."
Caley Thistle were denied silverware after losing a penalty shootout with Aberdeen at the weekend and Hughes felt his side fought back bravely, just days after heartbreak in the final.
"I felt we were the better team from start to finish," he said.
"We passed the ball and controlled the game. On another night we could have scored a few goals.
"But we are not going to go anywhere or achieve what we want to achieve if we keep conceding the goals we are conceding.
"The first one was a real lapse in concentration and it's goals that win games. It's as simple as that. It's a hard lesson but it's one I hope we can learn from.
"It's been great, it's been fantastic. There are no egos in the dressing room and these guys pick themselves up and go again."
Motherwell boss Stuart McCall admitted his team were second best, but was grateful for the three points.
"A win is a win. We didn't play particularly well, especially in the second half," he said.
"They started better than us but we got two really great, clinical goals. They passed it better than us and Gunnar Nielsen was excellent for us in goal.
"I've seen lots of games this season when teams have won and probably haven't been the best side and that was the case for us in this game.
"It's not often I've said that this season but it's a clean-sheet and three points and those are the bonus bits.
"We can play better and we will have to between now and the end of the season."