Sheffield United 3 Brighton & Hove Albion 1
Second-placed United were below par against Mark McGhee's south coast outfit who pulled off an impressive win over Leeds last week.
But goals from Phil Jagielka, Paul Ifill and Michael Tonge in the second half kept United 12 points ahead of the Elland Road side.
Steven Kabba squandered United's first chance after 16 minutes when he fired wide after David Unsworth's free-kick and soon afterwards Kabba's shot from 20 yards was deflected wide.
Unsworth's corner was headed down by Neil Shipperley but Guy Butters cleared.
The Brighton skipper made another last ditch intervention when Tonge swung in a dangerous ball from the right.
But Brighton keeper Michels Kuipers had to drop and make a sharp save when Kabba unloaded a 25-yard effort. Kuipers failed to hang on but Ifill crashed the follow up effort wide.
And when Leigh Bromby crossed from the right Jagielka's header fell meekly into the arms of Kuipers.
Brighton, who did United a favour with their win over third-placed Leeds last week, left United keeper Paddy Kenny untroubled in the first half.
Only a couple of long-range shots from Alexandre Frutos and a low cross from the left gave the visitors any hope of an upset.
But after the break United took control and set off on the road to another comfortable win when they grabbed the lead after 53 minutes.
Unsworth fed the ball out wide to Chris Armstrong and his scuffed low cross found Jagielka who volleyed past Kuipers from 12 yards out.
And United went further ahead after 64 minutes when Brighton youngster Joel Lynch was robbed by Ifill who darted forward and provided a crisp finish chipping his shot past Kuipers for his sixth goal of the season.
Fifteen minutes from the end Tonge rounded off the home side's scoring when he ran on to Kabba's through ball and hit his cool shot past Kuipers.
Substitute Colin Kazim-Richards grabbed a consolation goal for Brighton seven minutes from the end.