The Manchester United shot-stopper was the difference between the two teams, ensuring that the visitors snatch a point and furthering the doubt around Jurgen Klopp's ability to unlock well-organized sides.
It now appears to be the most predictable game in English Football when Manchester United visit Anfield, Mourinho executes his game plan to nullify the Liverpool attack and take a point against a difficult side.
That strategy was threatened 30 minutes in, Firmino's quick feet and the low cut cross was met by Joel Matip who was denied by a remarkable save from De Gea.
Moments after Liverpool's brightest spell in the match so far, United were presented with the opportunity to break the deadlock, Romelu Lukaku's composed effort, too close to the Belgian who parried to safety.
After the break, the Red's continued their positive start but it seemed the final touch was lacking. An observation, perfectly summed up by the home side's best opportunities of the second half. Joe Gomez's delicious cross was clipped over by Can from close range and a heavy cross from Coutinho was just too high for the on running Salah.
Despite, the introductions of Alex Oxlade-Chamberlain and Daniel Sturridge, who both looked lively, United hung on to snatch a point at a notoriously difficult ground.