London - John Terry's dismissal took the gloss off Chelsea's comfortable 4-1 victory over third-tier Peterborough United on Sunday, which took the Premier League leaders into the FA Cup fourth round.
Two goals from Pedro Rodriguez and strikes from Michy Batshuayi and Willian ensured Antonio Conte's side avoided any chance of an embarrassing slip.
But Terry's 67th-minute dismissal for fouling Lee Angol was a big blow for the 36-year-old, who was making his first appearance in two months after an injury lay-off and whose contract expires at the season's end.
Chelsea were leading 3-0 at the time and while Peterborough's Tom Nichols quickly reduced the deficit, Pedro's 75th-minute strike meant the hosts saw out the game comfortably.
Conte made nine changes to the line-up that started the 2-0 mid-week defeat by Tottenham Hotspur, the game that marked the end of the Blues' 13-game winning run.
The Italian took the opportunity to restore Terry to the side, while Kurt Zouma made his return after 11 months on the sidelines following a serious knee injury.
Youngsters Ruben Loftus-Cheek and Nathaniel Chalobah were also handed rare starts, but it was one of the more familiar names on the team-sheet that calmed any early home nerves.
Pedro took his 18th-minute opportunity superbly, but before then Conte's side had survived an early scare.
Peterborough started the game promisingly and while they had cause to be grateful that Gary Cahill's sixth-minute flick deflected off the post to safety, they should have taken the lead two minutes later.
A deep cross from Marcus Maddison was allowed to find its way to striker Angol, who was unmarked when he connected with a close-range volley that he directed wastefully at goalkeeper Asmir Begovic.
Peterborough manager Grant McCann had insisted his side had nothing to lose coming into the game and challenged his players to create a moment of history for the club.
Had they made more of that opportunity, or the one that presented itself when Ryan Tafazolli headed wide from a corner a few minutes later, Conte's side might have endured a more testing afternoon.
As it was, Chelsea made sure there would be no repeat of those early scares, taking control when Pedro pounced on the ball after Chalobah's shot had been pushed out by Luke McGee.
The Spain international cut inside one challenge and gave McGee no chance with a curled finish.
From that moment, there was little chance of an upset and Conte's side should have had the tie wrapped up before half-time.
McCann's side were fortunate to escape a strong penalty appeal when Tafazolli appeared to bring Batshuayi down inside the box and had an even greater let-off when Pedro struck the bar from six yards.
Batshuayi drew a frustrated response from his manager when he failed to play in Willian, who had a clear run on goal, instead trying to fashion his own shooting opportunity.
But the Belgium striker made amends two minutes before half-time when he was set up by Loftus-Cheek's lay-off, striking home his side's second goal with a low, right-foot shot.
The interval brought respite for the visitors, but when Loftus-Cheek fired wide moments after the restart, it was clear there would be no shift in the balance of the game.
A third goal quickly came when Pedro collected Cesc Fabregas's pass wide on the left and picked out Willian's forward run.
The Brazilian moved the ball onto his right foot and placed his shot beyond McGee from 20 yards out.
Terry's clumsy last-man challenge on Angol was followed by Nichols' close-range effort, but Pedro wrapped things up with another well-executed finish.