Ronaldo nets hat -trick, Pizzi, Goncalo Paciencia and Bernardo Silva shared the other goals in the one-sided Group B match.
Cristiano Ronaldo moved closer to reaching 100 goals for his international career.
Portugal are now second with 14 points, one ahead of Serbia, and will qualify if they win in Luxembourg on Sunday. Leaders Ukraine have qualified.
Ronaldo was quick was quick off the mark, winning and converting a penalty in the seventh minute.
The 34-year-old got to the ball ahead of Saulius Mikoliunas, who clipped his heel, and converted the spot-kick with a shot into the middle of the goal which hit goalkeeper Ernestas Setkus’ foot on the way in.
Lithuania suffered more losss 15 minutes later as they lost the ball in midfield and Paciencia slipped the ball quickly to Ronaldo who produced a wicked, dipping first-time shot which flew past the bemused Setkus from 25 metres.
He had another shot on the turn saved by Setkus and blasted over after bursting into the box before the break.
Pizzi, Paciencia and Silva scored in an 11-minute spell after halftime and Ronaldo sent two efforts agonisingly wide as the siege continued.
He completed his hat trick from Silva’s pass in the 65th minute before Paciencia set him up nicely for a fourth but Ronaldo fired over the