Leven scored a goal either side of the break and Sam Baldock fired in his second league goal of the season to ensure all three points.
And it could have been more with Aaron Wilbraham thundering the bar and Mark Wright firing over from close range.
The Glovers on the other hand came to stifle the Dons with a 4-5-1 formation that just didn't work on the day and left them woefully short up front.
Dons started brightly and Wright just curled wide early on.
But they continued to press and got their rewards on 20 minutes when Leven pounced from close range after Asmir Begovic just got a hand to Wilbraham's header.
In reply Yeovil hit the bar as Gary Roberts was afforded too much time on the edge of the box and hit a decent curling shot.
But moments later Wilbraham then thundered the bar with an almighty shot from 25-yards that left Begovic rooted to the spot.
Things were much the same after the break as Yeovil just couldn't put together attacks of any note.
And on 53 minutes Baldock got on the end of Wilbraham's flick, wriggled his way past Terrell Forbes and hit a left-foot shot that just squeezed in at the near post.
It was plain sailing from then on as Dons moved the ball around with ease.
Leven stung the palms of Begovic with a well-worked free-kick from 25 yards.
Yeovil could have got back into it, but skipper Terry Skiverton somehow headed into the side-netting from close range after Gavin Tomlin sent a precise cross to the back post.
And they were made to rue that miss as Leven finished a superb move 12 minutes from time.
The ball was played into Wilbraham's feet, he laid the ball to Leven who spread the ball out wide for Jarni Sturm. Leven then burst into the box where he got the ball back to smash home first time from 15 yards.
And things could have got even worse for the Glovers, but Wright blasted over Baldock's cut-back.