The most cruel of bounces off a wayward beach ball left the Black Cats purring and the Reds furious as Darren Bent netted the only goal of the game after just five minutes.
Andy Reid's cross was flicked out to Darren Bent by Steed Malbranque, and the Black Cats striker took a touch before firing at goal.
Seconds earlier a Liverpool fan behind Pepe Reina's goal decided to launch a beach ball on to the field.
And the Reds goalkeeper could only look on as Bent's shot deflected off the wayward ball to leave him stranded.
Liverpool's shocked looks soon turned to ones of anger as they realised that referee Mike Jones had allowed the goal to stand.
While there was no doubt that luck had played a major part in the Wearsiders taking their lead, in the minutes that followed they proved they were worthy of the advantage.
Bent could have extended the home side's lead on 22 minutes but headed straight at Reina from Reid's cross.
Before that Lorik Cana had headed over the bar as Sunderland looked to take the game to the Reds.
The hosts were clearly the better side in the opening half and looked the side most likely, while Liverpool were restricted to bit-part opportunities - Jay Spearing firing over from distance while Phil Bardsley had to clear a weak effort off the line as the half came to a close.
In the second half, Benitez's men stepped things up a gear. The Black Cats looked to be coping with the extra pressure, while trying to hit Liverpool on the break.
Reina pulled off a superb save to deny Bent on 54 minutes, and seven minutes later the Sunderland striker was also denied by the width of a post.
Things went slightly awry for Steve Bruce's side as two injuries almost changed the game. First Lee Cattermole was stretchered off on 57 minutes and seven minutes later Kenwyne Jones followed suit.
The Wearsiders lost their shape and almost their way as Liverpool began to throw everything they had at the hosts.
But in the end the visitors couldn't find the breakthrough they so desperately sought, thanks largely to the rearguard efforts of Michael Turner and Cana, who switched to centre-back.
Even seven minutes of added time at the end of the 90 weren't enough for the Reds to find a way through, although it did take a superb double save from Craig Gordon to deny both Dirk Kuyt and David N'Gog in the dying minutes.
The defeat could mean the end off Liverpool's already slim title hopes, but that won't worry anyone on Wearside, with the red and whites delighted to have leap-frogged the Reds in the table.
Bruce and his men will be walking tall tonight, while the Liverpool fan who set in motion what will no doubt be labelled beachball-gate has probably gone into hiding.