Odion Ighalo scored his first brace for Manchester United to guide them into the FA Cup quarter-final with a comprehensive 3-0 win at Derby County.
Luke Shaw broke the deadlock with an unstoppable volley just past the half-hour mark.
Ighalo doubled their advantage on the cusp of half-time and sealed the win with a thumping finish on 70 minutes.
Man United will host Norwich City in the next round, who beat Tottenham Hotspur on penalties on Wednesday.
Derby County came closest in the opening 20 minutes with chances through Louie Sibley and Wayne Rooney.
Scott McTominay was dispossessed outside his own penalty area and Sibley flashed a venomous effort wide of the far post from the edge of the box.
The headline writers had their pens at the ready when Rooney stood behind a free-kick situated 25 yards away from goal. He curled a dangerous effort towards goal but Romero dived low to palm the ball behind at his near post.
Man United grew into the match with Bruno Fernandes dictating play in the final third and Luke Shaw making inroads down the left.
Juan Mata forced Derby goalkeeper Kelle Roos into action from range and Roos had to be aware once again to foil Ighalo from close range.
Luke Shaw broke the deadlock when his volley deflected off Jesse Lingard into the far top corner. Fernandes and Lingard had strikes blocked and Shaw planted his volley into the ground and the ball simply whistled past Roos.
The visitors continued their momentum and felt aggrieved when referee Craig Pawson denied them a penalty. Fernandes believed his strike was blocked by the arm of George Evans and VAR would’ve perhaps reviewed the decision.
They doubled their advantage when former Watford striker Ighalo bagged his second goal for the club. Shaw once again engineered the move when he surged inside from the left to drive a pass into the Nigerian’s feet.
Ighalo shuffled between two defenders and poked a scrappy finish beyond Roos and into the bottom corner.
Derby’s evening went from bad to worse when they had to replace Tom Lawrence before the interval due to a suspected Achilles injury sustained from a challenge with McTominay.
The Rams reacted positively after the break and nearly drew level when Martyn Waghorn came within a whisker of reducing the deficit. Rooney switched the ball beautifully, Bogle delivered a whipping cross into the box and Waghorn glanced his header narrowly wide of the far post.
They produced a spirited performance during the second half but their adventurism left them vulnerable to the counter-attack. Roos prevented Shaw and Mata from extending United’s lead with two impressive saves at his near post.
Man United killed the contest when Ighalo doubled his tally for the night with 20 minutes remaining. Mata surged down the right and squared the ball to the former Watford striker. His initial strike was blocked but he thundered his follow-up into the roof of the net.
Jack Marriott came close to reducing the arrears when Romero was forced to turn behind his low drive from range. Lingard also had a chance at the other end which went just wide of the target.
Rooney nearly marked his appearance against his old club with a consolation when his curling free-kick was tipped over by Sergio Romero from the underside of the crossbar.
DERBY COUNTY: ROOS, BOGLE, EVANS, FORSYTH, LOWE, SIBLEY (SHINNIE 80′), BIRD, KNIGHT, ROONEY ©, LAWRENCE (WHITTAKER 44’), WAGHORN (MARRIOTT 67’). SUBS: HAMER, SHINNIE, CLARKE, MARRIOTT, MARTIN, DAVIES, WHITTAKER.
MAN UNITED: ROMERO, DALOT, BAILLY, LINDELOF, SHAW (WILLIAMS 80′), MCTOMINAY, FRED (MARTIAL 73’), MATA ©, FERNANDES (PEREIRA 66’), LINGARD, IGHALO. SUBS: DE GEA, TUANZEBE, MATIC, PEREIRA, MARTIAL, GREENWOOD, WILLIAMS.