Sheffield United manager Chris Wilder credited his team's fast start for winning the Steel City derby.
Goals from Patrick Bamford and Harrison Burrows inside the opening 20 minutes set the platform for the 2-1 win that relegated Wednesday to League One.
It was the fourth time in their past eight league matches at Bramall Lane that they have been two up by the interval.
"We blew them away with a big start," Wilder told BBC Radio Sheffield.
"We talked about our start against Stoke, Leicester, Birmingham, Ipswich and even Middlesbrough - they're top sides - and we blew the opposition away.
"After that 20, 25-minute period, we started taking an extra touch or looking for that killer ball too much instead of what we'd done in the first 20 minutes, which was to open them up and give them no opportunities to get a foothold in the game."
But rather than go on and secure a commanding victory, Kalvin Phillips' dismissal reduced them to 10 men before Charlie McNeill pulled a goal back for the Owls.
Wilder said: "We spoke at half-time about the eventualities of what can happen if we don't approach it in the right way. We talked before about how we're in complete control of this day and if we lose control, they're game and have a puncher's chance.
"And we gave them an opportunity with a decision Kalvin made. You can't say it was anything but a red card, and on top of that, a great finish to get them back in the game. Then it was game on.
"Then we had to show the different qualities, even though they never really opened us up apart from a couple of little forays we dealt with comfortably."