Saracens director of rugby Mark McCall felt the second-half sin-binning of Billy Vunipola was the turning point for his side as they fought back from an early deficit to claim a 27-9 Champions Cup victory over Ulster.
Ulster scored the first nine points of the match and still led 9-5 at the interval as Saracens struggled to find a way through the home side's defence at the Kingspan Stadium.
The visitors then looked to be in further trouble when they were reduced to 14 men in the 54th minute when England forward Vunipola was shown a yellow card.
That was the second player Saracens had sent to the sin-bin after Michael Rhodes' early misdemeanor but rather than fold in the face of adversity, McCall believes it helped galvanise his side into action as they scored 22 unanswered points in the final 21 minutes.
He said: "We had to work really hard for it.
"The first 20 minutes we hadn't done all that wrong but we were 9-0 down and I think that's what that team has; they are very experienced and very resilient and found a way to claw their way back into the game in the second 20 minutes of the first half.
"But I think the turning point came when Billy Vunipola got sin-binned and I think that moment when they got into our 22 and we won a penalty the next eight minutes were wonderful and we got a strong, resilient team performance.
"At half-time, 9-5 was ok for us and we'd chosen to play into the strong breeze but then when we didn't capitalise on the pressure we had built early in the second half we were a little bit worried when Billy got sin-binned.
"But I thought we were magnificent in that 15-minute period. Our half-backs were superb, they probed the corners and ran at the right times."
The bonus point win leaves Saracens at the top of Pool One on nine points, with Oyonnax, Ulster and Toulouse yet to pick up any points.
Saracens go to Oyonnax - whose opening game against Ulster was postponed following the Paris terror attacks - next up as they look to further strengthened their place at the top of the table.
Former Ulster coach McCall was not getting carried away though, adding: "You don't underestimate anybody and we'd been hoping that Ulster would be the first team to have played Oyonnax.
"We've now got to go and do a real professional job there and then bring them back to our place.
"If we can win those two games then we're in a really good position."
The Aviva Premiership leaders scored the game's only tries through Chris Wyles, Alex Goode, Duncan Taylor and Billy Vunipola with the touchdowns from Goode and Taylor being scored when the visitors were down to 14 men.
Ulster's director of rugby Les Kiss was hugely disappointed at seeing his side lose control of a game which they had looked in charge of midway through the first half.
"In the first 20-25 minutes we positioned ourselves well and that 10-minute period in the first half we didn't take advantage of that and put our foot to their throats," he said.
"Getting their try just before half-time allowed them to build some confidence.
"When we had a chance to assert ourselves in the second half and put them under pressure we just didn't work hard enough to make those opportunities come our way."
He added: "It was a typical Saracens performance and full credit to them, they hurt us.
"When you leak four tries at home, that's a bad place to be. It certainly puts us on the back-foot, without a doubt."