The absence of Fredi Kanoute - on African Nations duty for Mali - presented the Portuguese international with a chance to shine in the Premiership and he certainly didn't disappoint and seized his opportunity with what was the winning goal - pouncing on a precision ball from sub Johnnie Jackson on 53 minutes.
It is actually two goals in two starts now for the young striker, who netted against Sunday's FA Cup opponents Manchester City the last time he was on from the beginning in the Carling Cup before making way for Fredi.
"It was an opportunity for him and he is in there now," said David of Helder. "He's had a difficult time and it is hard for any foreign player, but he has got a goal and he played with some sparkle and energy.
"He worked very hard and that is so vital to our team - the front players closing down the defenders in front of them. It gave us a chance and we capitalised."
Another to make the most of his opportunity on Saturday was new boy Michael Brown, who put on a tenacious performance on his first team debut for the club. David revealed that Michael was likened to the great Dave Mackay after game - a comparison he doesn't really go along with.
"Fortunately for us we knew that he played against Liverpool twice last year and coped with it. I'm absolutely sure, having seen him play in the game and his attitude in the reserves last week, that he is a spot-on professional.
"Someone after the game said to me that he reminded them of Dave Mackay. Even with the greatest will in the world, there won't be another Dave Mackay at this football club.
"I said that Mackay was bigger than Brown for a start, but they contended that he was about 5ft 9.5" - I always felt he was a bit bigger than that.
"Dave Mackay was supreme. Michael reminded me a little bit of Alan Ball - perpetual motion, plays the ball early, doesn't give it away and gives it quickly. When the other team have possession he is magnificent in closing down and making it difficult for them to get going."
David Pleat reflected that Helder Postiga performed with some 'sparkle and energy' in his display against Liverpool last weekend.