Demba Ba made an immediate impact on his Chelsea debut in the FA Cup by scoring twice as the holders thrashed Southampton 5-1 on Saturday, while Newcastle were the only Premier League side to be ousted by lower-league opposition in the third round.
Ba completed his move from Newcastle on Friday and took just 35 minutes to score at Southampton to cancel out Jay Rodriguez's goal.
After further Chelsea goals from Victor Moses and Branislav Ivanovic, Ba netted his second before Frank Lampard wrapped up the rout from the penalty spot.
The goal saw Lampard become Chelsea's joint second highest goal-scorer of all time alongside Kerry Dixon.
England midfielder Lampard's second-half penalty, the fifth of the game for the FA Cup holders, put him on 193 career goals for the London club.
Bobby Tambling leads the way with 202 goals.
Lampard, 34, who came on in the 64th minute for Branislav Ivanovic, smashed home his spot kick 18 minutes later after a cross from fellow substitute Marko Marin was handled.
The penalty also helped Lampard join Tambling as the club's highest FA Cup scorer on 25 goals.
The cup provided no respite for Newcastle from their Premier League struggles, with Alan Pardew's side losing 2-0 at second-tier club Brighton.
But Manchester City had no trouble ousting another League Championship club, Watford, with a 3-0 victory.
Robin van Persie saved Manchester United's bacon against West Ham scoring an injury-time equaliser to secure a 2-2 draw and earn a replay at Old Trafford.