Mas beat Briton Oscar Onley in a two-man sprint finish to claim the win and extend his lead over four-time former winner Primoz Roglic, who finished third at 12 seconds.
The Slovenian now trails Spaniard Mas by one minute 18 seconds, with Austrian Felix Gall, who shipped 18 seconds in finishing fourth, third overall at one minute 39 seconds.
Onley, who leads the best young rider category, moved up a place to fourth at two minutes and 20 seconds as former winner Sepp Kuss tumbled three places to seventh overall after coming home one minute and 44 seconds behind Mas.
Five-time Tour de France winner Pogacar had been dominating the race until he crashed heavily on Saturday, breaking his collarbone.
He was leading Mas by three minutes 50 seconds when he fell, and he also suffered a concussion.
He is due to undergo surgery on his broken collarbone.
"Now I understand Tadej - the red jersey gives you wings," smiled Mas, who said that he felt in the form of his life.
His victory on the 187.4km mountainous stage from Villajoyosa to Alto de Aitana ended his Spanish team Movistar's five-year win drought at their home Grand Tour.
"The team was 10 out of 10, we controlled the situation really well, and I felt good in the finish," added the stage winner.