Chelsea advanced against opposition from the League Championship, beating Hull 4-0 with Willian scoring twice and Olivier Giroud netting his first goal since joining from Arsenal.
Back in favour at Leicester, Riyad Mahrez helped the team reach the FA Cup quarterfinals by resuming his lethal partnership with Jamie Vardy on Friday.
Vardy earned Leicester a 1-0 win over second-tier Sheffield United in the fifth round by heading in a cross from Mahrez, who was starting for the first time since the collapse of his move to Manchester City at the end of the January transfer window.
Mahrez spent more than a week in self-imposed exile after being denied a transfer to the English Premier League leader, missing two games and a string of training sessions.
He began his reintegration by going on as a substitute last weekend — coincidentally in a league match against Man City — and was given a standing ovation by Leicester fans when substituted in injury time on Friday. He applauded them back.
"The most important thing in the game was the fans supported Riyad," Leicester manager Claude Puel said, "and when I replaced him, it was a good feeling with the fans. It's important to stay united about this."
Vardy and Mahrez linked up to devastating effect when Leicester stunned the soccer world by winning the Premier League in 2016.
During that memorable season, Vardy set a record by scoring in 11 straight league games and the England striker is on another run, having scored in five straight games in all competitions.
His latest goal was a far-post header that looped over the goalkeeper in the 66th minute, following a cross from the right by Mahrez.
"To see Riyad and Jamie play together again on the pitch was a good feeling," Puel said.
The goal would have given Vardy extra satisfaction, considering he is a boyhood Sheffield Wednesday fan.
PASSING THE AUDITION
With Eden Hazard rested, this was a chance for other members of Chelsea's attack to stake a claim for a starting place in next week's Champions League match against Barcelona.
They didn't disappoint.
Giroud, Willian and Pedro Rodriguez, the three-pronged forward line, all scored in the first half against Hull as Chelsea roared into a 4-0 lead by the 42nd minute.
Both of Willian's strikes were from outside the area and came off passes by Giroud, who scored the fourth with a neat near-post finish from a cross by debutant Emerson Palmieri. Cesc Fabregas set up Pedro's goal with a superb pass over the defence.
Chelsea manager Antonio Conte now has plenty of options up front for the last-16 first leg against Barcelona, with Giroud vying with fit-again Alvaro Morata for the striker spot while Pedro and Willian are competing for a place alongside Hazard.
"For sure when I go home, I have many good doubts," Conte said.
Chelsea reached the quarterfinals for the 12th time in 17 seasons.