Junior continued his red-hot run of form in front of goal as Walsall secured their fourth successive home win against Wimbledon at Bescot.
The Brazilian marksman grabbed his ninth goal in his last 14 appearances with a second-half free-kick to seal Walsall's win that had been set up by a first-half opener from winger Darren Wrack.
But Walsall really owed their success to goalkeeper James Walker who pulled off a series of stunning saves to deny Wimbledon's leading scorer, David Connolly.
Walsall made the perfect start when Wrack finished off a neat three-man move after just 11 minutes.
Right-back Darren Bazeley floated the ball into the area and Junior nodded his cross down into the path of Wrack.
The former Grimsby Town wideman was under pressure from Mark Williams but he held off the attentions of the central defender to fire a low shot past goalkeeper Kelvin Davis.
But Walsall's advantage would have been a short one if it had not been for Walker who gave a sign of what was to come when he pushed a long-range drive from Williams around the post just two minutes after Wrack struck.
While Walsall did threaten to add to their advantage through strikers Jorge Leitao and Junior, Wimbledon should really have forced their way back on to level terms before half time.
Connolly squandered three clear-cut chances, failing to hit the target with his first two openings before being denied by Walker on the stroke of half time.
The Republic of Ireland international marksman was picked out by a neat cross from Jermaine Darlington only to see his point-blank header saved by Walker.
Connolly's frustration in front of goal continued at the start of the second half. He was again twice denied by Walker who held on to his long-range drive in the 47th minute, before diving bravely at Connolly's feet 60 seconds later.
Connolly's inability to convert the close-range chance was a let-off that Walsall took full advantage of and they sealed their success through Junior after 62 minutes.
The Brazilian scored direct from a free-kick after Leitao had been dragged down on the edge of the area by Mikele Leigertwood.