Former United goalkeeper Sam Johnstone saved Fernandes’ initial effort from 12 yards but VAR intervened as replays showed he had crept off his line and the Portugal international made no mistake second time round.
Just ten minutes earlier, the visitors looked to have won a spot-kick of their own after Fernandes brought down Conor Gallagher but referee David Coote decided United’s talisman had touched the ball after reviewing the play on his pitchside monitor.
Discussing the performance with MUTV shortly after the final whistle, Fernandes said: ‘It was a tough game. They play really good football, they are tough at the back and really strong.
‘I think we can do much better in the final third, last pass and shooting we need to do much better and I think everyone feels the same.
‘The performance was good but I think we can do much better and everyone agrees with this.’
Fernandes added: ‘We know it was a tough game today and we have a clear chance to score and I have to score to help my team-mates to the three points because we needed three points in the league.
‘The most important thing today is the three points.’
A clearly frustrated Fernandes claimed United’s entire dressing room were in agreement that the display they produced against the Baggies was below par.
‘If we had scored in the first half the game could have been much easier because maybe they open up the game a bit more for us,’ he continued.
‘But we had chances to score and I think – like I said before – everyone agrees we can do much more.
‘The performance was good but I think we can have a better performance than this.
‘We have showed already that we have more qualities than we showed today.’