Sunderland dominated the match with their passion and slick passing, while Leeds were second best in every department.
For Keane it was the perfect response from his team and a great start to his managerial career.
It was Leeds' third home defeat of the season - as many as they suffered in the whole of last term - and with them in the bottom three, Blackwell's position must be in doubt.
It took Sunderland 15 minutes to settle into the game and then they started to take Leeds slowly apart.
Their passing was more precise, their running more intelligent and their confidence was as high as Leeds' was rock-bottom.
Daryl Murphy was a constant danger up front and with Graham Kavanagh running things in the middle of the park, it was mostly one-way traffic.
Inevitably when the breakthrough came it was Liam Miller, who spent last season at Leeds, who got the goal.
He'd already had one header blocked by Stephen Crainey but there was no mistake when Ross Wallace calmly picked him out and he fired past Tony Warner.
Ironically it was the Irishman's first goal at Elland Road.
Leeds were hanging on, hoping to claw their way into the game, but they were hit by a goal either side of half-time and were dead and buried.
Kavanagh made a superb run forward to fire past Warner in the 45th minute and three minutes into the second period, substitute Stephen Elliott latched on to a Murphy header and lashed it past the keeper.
Blackwell had sent on Kevin Nicholls at half-time for the ineffectual Eddie Lewis. It was the midfielder's debut after picking up an injury in pre-season.
He soon added Seb Carole - who most Leeds fans had expected to start - plus Robbie Blake but it was asking too much.
With Sunderland losing two strikers to injury, Leeds were able to push forward a bit more but they still didn't look as they were likely to score from open play.