LONDON — Holder Chelsea had to step up a gear in the second half to reach the FA Cup quarterfinals Saturday in a 4-1 home victory over second-tier Cardiff.
The Premier League leader was being held 1-1 at halftime after Didier Drogba's second-minute goal was canceled out by Michael Chopra.
"They caused us a lot of problems in the first half," Chelsea assistant manager Ray Wilkins said. "But thankfully we managed to up the tempo in the second half."
Chelsea took control after the break as Michael Ballack, Daniel Sturridge and Salomon Kalou scored to extend the club's unbeaten home run to 37 matches.
Also Saturday, Portsmouth scored three times in 10 minutes as the financially troubled club earned a 4-1 victory at south-coast rival Southampton and a rare moment of joy for the Premier League's cash-strapped bottom club.
Reading's Jimmy Kebe scored after nine seconds - one of the fastest FA Cup goals - but ended up drawing 2-2 with fellow League Championship side West Bromwich Albion to force a replay.
Birmingham came from a goal down to beat second-tier Derby 2-1 with Liam Ridgewell scoring a last-minute winner.
In the late match, Manchester City hosted Stoke in an all-Premier League fixture.
Chelsea was the only top-four club in action this weekend as Manchester United, Arsenal and Liverpool had already been eliminated from the FA Cup.
The Chelsea defense was shorn of captain John Terry, who has been allowed to travel to Dubai to see his wife following newspaper allegations about his private life, and left back Ashley Cole, who is out for three months after breaking his left ankle.
It didn't seem the duo would be missed when Jon Obi Mikel's through-ball from the halfway line fell into Drogba's path and the Ivory coast forward flicked it over goalkeeper David Marshall.
But Drogba's fourth goal in three games since returning from the African Cup of Nations didn't curb Cardiff's ambitions.
It took a one-handed save from Chelsea goalkeeper Henrique Hilario to turn Anthony Gerrard's header wide. From the resulting corner, the unmarked Chopra nodded just over.
Drogba tried to double Chelsea's advantage with an overhead kick from six (meters), but Marshall was equal to it.
Cardiff's aerial threat was unsettling Chelsea and the 2008 finalists leveled in the 34th when Chopra evaded his marker and headed low into the net from Chris Burke's cross.
Chelsea replaced the ineffective Joe Cole with Kalou at the break, with Wilkins saying that the England winger still needs time to get back into "tip top form" after returning in September from an eight-month injury layoff.
Chelsea went back in front in the 51st minute when Drogba chipped through to Ballack and the Germany midfielder lifted the ball over Marshall.
Cardiff never provided the same threat or resilience as it had in the first half - and Drogba turned provider again for Chelsea's third in the 69th.
His initial shot came off the Welsh side's defense and Sturridge pounced, poking the ball through Marshall's legs to score for the third consecutive round.
Kalou headed in the fourth in the 86th being left free by two defenders to connect with Paulo Ferreira's cross.
"The scoreline looks like it's been a bit of the drubbing, but that bit of quality has come through for them," Cardiff manager Dave Jones said. "We gave a good account of ourselves."
In the other early kickoff, Portsmouth was pegged back by third-tier Southampton after Quincy Owusu-Abeyie put the Premier League's bottom club ahead in the 66th minute.
But after Rickie Lambert leveled, Aruna Dindane, Nadir Belhadj and Jamie O'Hara scored between the 75th and 85th minutes for Pompey to clinch a place in Sunday's draw.