There are occasional mistakes in the live performance but below are the full intended lyrics:

Earth's under attack from outer space
Flash Gordon is called upon to save the human race
With Dale Arden and Doctor Zarkov
They board Zarkov's rocket ship and strap in for liftoff

3, 2, 1, go!
Ready to launch
Blasting off
Go!

To outer space
To save the Earth from
The Planet of Peril
Mongo!

Flash, Dale and Zarkov on the Planet of Peril
Caught by Yellow-Men and brought to Ming the Merciless
Emperor of the Universe
Dale must be his bride and Flash must die are his orders

Flash leaps at Ming
Guards hold back Flash
And throw him
Go!

To Ming's arena
To fight Red Ape-Men
Onrushing Red Ape-Men
Go!

But Flash Gordon don't need no ray-gun to save the human race
He just curls up his fist and decks those Ape-Men right in the face
Knocking down Ming's evil forces with mighty, pounding blows
Saving the whole universe, whoa-oh-oh

Whoa-oh-oh oh-oh-oh

Flash Gordon alone and on the run
Forms an alliance with Prince Thun of the Lion-Men
Together they fall into a trap
Caught by Yellow-Men under Emperor Ming's command

Shark-Men drag Flash
Underwater
To their Underwater Kingdom
Go!

To their arena
To fight Green Shark-Men
Onrushing Green Shark-Men
Go!

But Flash Gordon don't need no ray-gun to save the human race
He just curls up his fist and decks those Shark-Men right in the face
Knocking down Ming's evil forces with mighty, pounding blows
Saving the whole universe, whoa-oh-oh

Whoa-oh-oh oh-oh-oh

Flash Gordon on the run again
Joins another foe of Ming
Prince Barin, leading Yellow-Men
Who turned against Ming's army

From up high Hawk-Men dive
Ming's winged minions who fly
Snatch Flash and Prince Barin up
And bring them to their Cloud Kingdom

Bound in chains
As Hawk-Men's slaves
In the Atom-Furnaces

Flash comes across
Doctor Zarkov
And Prince Thun of the Lion-Men

Zarkov hatches a plan
To escape from the Hawk-Men
Blow up the Atom-Furnace Hall
And make the whole Cloud Kingdom fall

As it collapses he shows the Hawk-Men
That only he can save their Cloud Kingdom
So they have to free Flash and his band
Whoa-oh

Emperor Ming
Shows up with his army
Demanding to torture Flash

The only way
That Flash can be saved
Is to enter the Tournament of Death

Fighters from every race on Mongo
Fill the planet's greatest arena
To slay each other with Flaming Lance
And do the Poison Dagger Dance

Flash Gordon stands victorious
So Ming the Merciless
Has to set him free again
Whoa-oh

Dale Arden a bride of the Emperor
Flash Gordon finally on his way to rescue her

Doctor Zarkov's Invisibility Machine
Renders Flash unseen
Go!

Invisible, Flash saves the one he loves
Then springs right past Yellow-Man armed with swords and ray-guns

To Ming's Throne Hall
To confront Ming
Flash leaps at him
Go!

Flash Gordon don't need no ray-gun to save the planet Earth
He just curls up his fist and decks the Emperor of the Universe
Knocking out Ming the Merciless, baby, with mighty, pounding blows
Punching him right in the face Whoa-oh-oh

Flash Gordon's got slick blonde hair and a BLAZING ATOM on his shirt
He throws aside his sword and ray-gun and punches out Ming the Merciless
Saving the whole universe, baby, with mighty and pounding blows

Whoa-oh-oh oh-oh-oh

Whoa-oh-oh oh-oh-oh

Whoa-oh-oh AHH!!!

FLASH GORDON!