London - Jermain Defoe's double helped Sunderland to a 4-0 hammering of fellow Premier League relegation battlers Crystal Palace on Saturday and left their former manager and now Palace handler Sam Allardyce plenty to think about.
David Moyes' side fully deserved their triumph which moved them alongside Palace in the Premier League table - though their goal difference is slightly worse than the London team - albeit with both sides still in the relegation zone.
The visitors - whose goal haul equalled the amount of away goals they had scored in their previous away matches this term - took the lead after 10 minutes.
Lamine Kone rose highest at the far post to meet a Sebastian Larsson free-kick with a looping header that Wayne Hennessey dropped under pressure from Billy Jones.
Now falling to the ground, Kone still managed to steer the ball home.
The only worry for Moyes was the trouble that Larsson was having in containing lively Ivory Coast winger Wilfried Zaha.
Having been booked after six minutes for a sliding tackle on the Palace forward in the sixth minute, the midfielder then tripped Zaha again in the 21st minute.
The resulting free-kick eventually found Damien Delaney who curled over a delightful cross which fellow central defender James Tomkins could only head wide.
The home side were further hampered after 27 minutes when French international Yohan Cabaye was forced to limp off to be replaced by Joe Ledley.
Sunderland were having an unexpectedly comfortable afternoon, one which improved in remarkable fashion in the five minutes prior to half-time.
First, the impressive Didier N'Dong, Sunderland's record signing who is beginning to find his feet since returning from the African Cup of Nations, drove forward, shrugged off the attentions of Ledley and curled a low shot into the corner of the net.
Next, in the opening seconds of injury-time, N'Dong spread the ball out to Adnan Januzaj who in turn picked out the run of Defoe.
The veteran striker held off Scott Dann again and sent an unerring shot beyond the diving Hennessey.
Much to the disbelief of all those inside Selhurst Park, there was still time for another Sunderland goal before the break.
This time, it was Januzaj's turn to send a diagonal ball into the path of Defoe and Delaney's turn to be turned. The end result was the same - a low shot past Hennessey.
Defoe had helped Allardyce pull off a miraculous escape from trouble at Sunderland last season. Here he was causing the former England manager crushing embarrassment.
As the whistle sounded for half-time, the mood turned ugly.
A chorus of "You're not fit to wear the shirt" cascaded down from the stands. Even worse, one Palace fan decided to take matters into his own hands by running on to the pitch and confronting Delaney.
He was frogmarched from the pitch.
Whatever the Palace manager said to his players will have been brief as they were sent back out on to the pitch five minutes early.
In spite of the introductions of both Andros Townsend and Loic Remy, Palace could do little to break down a stubborn Sunderland defence in a second half that was largely a non-event.
A Christian Benteke overhead kick at the end of a goalmouth scramble in the 65th minute flew high over the bar and summed up their ineptitude.
Indeed, Sunderland might have added a fifth goal at the other end when Januzaj swept a left-foot shot just wide.