Smith scored 61 runs from 41 balls and laid the platform for the run-chase, which seemed improbable in the start.
Both players had a heated altercation in the second T20I.
Shadab fired in some inappropriate comments after dismissing Windies opener, Walton.
Pakistan won the 2nd T20I by 82 runs to take a 2-0 lead in the series.
Pakistan beat Windies by 82 runs.
A much weakened West Indies side will take on Pakistan in the first match of the T20I series.
Here are the top cricket headlines of the day.
The Titans acquired the services of Sri Lankan legend Mahela Jayawardene as their head coach earlier, which is sure to be a huge plus for the squad.
Trinbago Knight Riders and St. Kitts Nevis and Patriots will lock horns for one final time on Sunday for the title.
Twitter hailed Luke Ronchi, Rashid Khan, Warriors and suggested the defending Champions to hold their head high.