Willian dispatched two inch-perfect finishes as Chelsea cruised past Hull 4-0 and into the FA Cup quarter-finals.
The hard-grafting Brazil forward's smart brace sealed a comfortable Stamford Bridge victory stroll, with Olivier Giroud bagging his first Chelsea goal and Pedro also on target before the half-time whistle.
Willian also showed his savvy side, however, appearing to distract David Meyler with a cheeky comment just before the Hull midfielder missed a second-half penalty.
Meyler turned around and ruffled Willian's hair - with both men all smiles - but the Hull star's tame spot-kick was then saved by Willy Caballero.
And so the 29-year-old forward's low-key labours and wily interventions paid huge dividend once more for Chelsea.
Chelsea proved so dominant as to coast through the entire second half, with under-fire manager Antonio Conte applauding fans for lending support by pointedly chanting his name.
They punished Hull's nerves without mercy, claiming all four goals in a ruthless first-half showing.
Willian whipped home the opener from 20 yards in just the second minute.
The Brazilian skinned Kevin Stewart, picked his spot and dispatched a stylish opener, that kick-started a goal glut to stun the visitors.
Giroud missed two fine chances with Pedro failing to latch onto a smart throughball in between those failed efforts for the French forward.
Chelsea hardly had to wait for their second goal however, with Pedro hauling down a fine pass from Cess Fabregas, and drilling home.
And when Giroud mugged Stewart just outside the box, Chelsea killed any remaining shred of a Hull fightback. The former Arsenal hitman fed Willian, and the 29-year-old duly rifled in another accurate finish from distance.
Giroud even troubled the scorers himself before the break, stretching backwards smartly to poke home at the near post from Emerson's low cross.
Hull started the second half the brighter, with Harry Wilson drawing a foul and penalty from Fabregas.
Caballero easily dealt with Meyler's tame penalty however, thanks potentially in some small part to Willian's word.
The Chelsea goalkeeper then denied Nouha Dicko with another smart intervention, and one that roused the Blues from their second-half slumber.
Determined to complete his hat-trick, first Willian was just unable to work space to drill home - then saw another teasing effort rebound off the upright.
Sheffield Wednesday fan Jamie Vardy put the Blades to the sword as Leicester knocked Sheffield United out of the FA Cup.
Sheffield-born Vardy, released by the club he supports at the age of 16, had been the target of "Owls reject" taunts by the visiting supporters, but he had the last laugh when he headed the only goal of the game after 66 minutes.
The fifth-round tie was the first game the striker had started in this season's competition, having previously played just 10 minutes of the replay against his former club Fleetwood last month.
Leicester boss Claude Puel also saw fit to play all his other big hitters, paying full respect to the Championship challengers as he named a full strength team.
That meant Riyad Mahrez made his return to the starting line-up - and was back at the King Power Stadium - for the first time since going AWOL after the collapse of his proposed transfer to Manchester City.
The Algerian received a warm reception from the Leicester fans, and a standing ovation when he was substituted late on, but was slow to get into the match as Sheffield United proved competitive opposition, playing tidy football but without really threatening Kasper Schmeichel.
Vardy got his first glimpse of goal after 10 minutes. A good first touch from Wilfred Ndidi's pass set up the shooting opportunity, but his effort from the left side of the penalty area was deflected over the crossbar by Jake Wright.
Shortly afterwards, from a similar position, Vardy curled an attempt narrowly wide of the far post.
Sheffield United goalkeeper Jamal Blackman was worked for the first time midway through the first half when he had to push away a 25-yard strike from NDidi.
Despite being under pressure for the most part, the visitors had a golden chance to take the lead just after the half hour mark. Samir Carruthers' deflected cross saw the ball drop invitingly for Enda Stevens 10 yards out, but former Blade Harry Maguire slid in to make a last-ditch block and prevent an almost certain goal.
Vardy was presented with a third chance from the left side of the area when Mahrez put him through one-on-one with Blackman. He hit the target this time, but the onrushing goalkeeper made the save with his legs.
Leicester tried to maintain their pressure in the second half, but they were largely kept at arm's length.
Mahrez and Demarai Gray were menacing on the break and Vardy's pace in behind the defence was always a danger, but the visitors were marshalling the threat well until Mahrez got free down the right and clipped a cross to the far post where Vardy looped a header back across goal and into the net.
Blackman denied Gray a quick second goal before opposite number Schmeichel kept his side ahead and ensured they progressed to the quarter-finals with a good save to thwart George Baldock as Sheffield United posed a rare threat.