Owen Farrell kicked 14 points and David Strettle scored against his old club as Saracens raced into a 19-3 lead in front of a record-breaking 82,000 crowd on Tuesday.
Harlequins mounted a comeback with a try from Joe Marler but Saracens defended valiantly to end their unbeaten start to the Aviva Premiership season.
Brad Barritt was the official man of the match but the award could have gone to flanker Andy Saull, who took his chance in the injury-enforced absence of Jacques Burger.
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"I thought Andy Saull was absolutely magnificent and from an England perspective I thought a lot of our young, English players really made a good impression today," McCall said.
"Brad Barritt, who is just getting better and better, Owen Farrell again and Alex Goode who has really come into form in the last month or so.
"Ben Spencer (the scrum-half) really helped to close the game out and (lock) Mouritz Botha did well when he came on too.
"Hopefully they (the England coaches) will take notice and I'm sure some of the Quins players have put themselves forward as well.
"Charlie Hodgson can't be forgotten either - some of his long passes today were outstanding and I don't think anyone else in England can pass the ball like him."
Harlequins director of rugby Conor O'Shea joined McCall in praising Farrell, who did not miss a kick and shows all the poise of a Test player in waiting.
Six years ago, O'Shea was in charge of identifying the next generation of England stars and Farrell has been on his radar since he was just 14.
"I am sure he will be a cornerstone for England for a long time," O'Shea said.
"I saw him at Loughborough in a training camp when he was 14 and it was an under-18 camp and he ran the show.
"He's an outstanding player."
Saracens did not score a point after the 24th minute but their intensity in that opening quarter - followed by a lung-bursting defensive effort - won them the game.
"That was a brilliant result for us and a good performance in two contrasting halves," McCall said.
"We were in control in the first half but in the second half Quins showed why they are top of the league.
"They played scintillating, off-loading rugby and we had to be at our very, very best to stop them. We scrambled really well and we had to.
"We have won four games in a row and this win was against the top side in the league. We put everything into that match and there are a lot of battered bodies now.
"Quins are still ahead of us in the table so it was good that we were able to deny them a bonus point which they probably deserved."
O'Shea was left to rue his side's error-strewn start.
"To give a lead like that to the Premiership champions was going to be difficult to claw back," O'Shea said.
"Our guys fought tooth and nail to get back into it and tried to play as much rugby as we could.
"When you look back you will probably see three opportunities we didn't take. At this level you have to take them."
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