Ray Wilkins was impressed by Chelsea's power, especially in the second half, as they beat Southampton 3-1.
Stamford Bridge was silenced in the first minute of Sunday's Premier League clash when Jay Rodriguez punished a Michael Essien error to put Saints ahead.
But second-half goals from Gary Cahill, John Terry and substitute Demba Ba produced an emphatic turnaround and kept the Blues hot on Arsenal's heels in the title race.
"Chelsea were a totally different side in the second half," Wilkins told Sky Sports. "They came out and played with real energy."
"A lot of that was down to Frank Lampard and Ramires in the middle of the pitch. They moved the ball quicker and the energy levels were totally different.
"Southampton could not live with them and Chelsea could have scored a couple more.
"That is the sign of a really good side; they did not play well in the first half so they have rolled their sleeves up and come out and given it a really good go in the second half and they were very good."
It was a landmark game for John Terry, who made his 400th Premier League appearance durign which time he has has scored 34 goals and played under 10 managers.
"It is a marvellous achievement for one player to stay at one club in the modern game and play as many games as he has played," added Wilkins.
"Top clubs are always looking to improve their side year after year and for John to reach that landmark is quite fantastic for him."
Jamie Carragher agrees and says that Terry does not get enough credit for what he does.
"Terry is a great defender. He gets goals but I don't think he gets enough credit for his technical ability on the ball," said Carragher.
"For me if you talk about Premier League defenders over the last 20 years, he would be right at the top.
"He is not the quickest of players and the reason he has played so long is because he has got such a great understanding of the game.
"Reading the game is one of his great strengths."