Things looked to be going wrong for the hosts when a slow start was compounded by having midfielder Tino Costa sent off in the 28th minute.
But Mallorca could not take advantage and went behind in the 59th minute when Ricardo Costa headed Valencia in front.
Roberto Soldado doubled the lead in the 81st minute to boost his side's top-four hopes and leave Mallorca rooted in the bottom three.
Mallorca were the first to threaten with Alejandro Alfaro seeing his shot tipped over by Diego Alves.
The home goalkeeper had to be alert again to parry a right-footed effort from Giovani Dos Santos from 18 yards before Mallorca got a further boost shortly before the half-hour mark.
Tino Costa was shown a straight red card for a bad foul on Jose Nunes to leave the hosts to play for more than an hour with a man less.
But it was the 10 men who struck first 14 minutes after the break.
Sergio Canales swung in a corner from the right and defender Ricardo Costa rose to head it home from the centre of the area.
Mallorca pressed in search of a leveller with Jose Luis Marti heading wide and Tomas Pina over from corners.
But it did not come and instead the visitors were undone again at the back.
Dani Parejo's pass set up Soldado, who made no mistake with a low right-footed finish.
Diego Alves produced a fine double save in injury time to deny Mallorca even a consolation, parrying first from Giovani and then from Marti as the visitors were left frustrated.