Frank Lampard has told Chelsea the title race remains on as he targets a fourth Premier League winners' medal and a first with Manchester City.
Lampard, Chelsea's record goalscorer, scored the equaliser in September's clash with the Blues but was unable to force a winner in the return fixture as Jose Mourinho's men survived a City siege to draw 1-1 on Saturday.
The 36-year-old midfielder scored a club record 211 goals in 13 years at Chelsea and won three Premier League titles, but could be a key figure in City's title defence after leaving Stamford Bridge last May.
The draw meant City remain five points behind Chelsea with 15 games to go.
"You lose and it's eight points difference and the league will become a bit more clear," Lampard said.
"Now it's very much lots of points to play for and it's on. It's important to keep focused.
"The draw keeps the league bubbling. Chelsea are obviously the favourites as they're five points ahead.
"It doesn't change anything and Chelsea will be happy with that but we can't be too upset."
Lampard joined City ahead of a move to New York City FC, having previously said he would never play for another Premier League club.
He might have expected a muted reception from Blues supporters, but, bar the odd dissenting voice, he was well received from fans who held him so dear for so long.
"I was excited but also a bit nervous to come back here," said Lampard, who came on as a substitute 13 minutes from time.
"But I enjoyed it. I have to give my best when I come on the pitch and I was delighted with my reception.
"City fans have been brilliant since I've been here. I appreciate that.
"They might not have known what to expect from me when I came here. Would I come here and just jolly up for five months and then go away to America?
"They can see when I play I try to give everything and then I came back here after 13 years and got a great reception at the end.
"When you play for a long time it is nice to have that rapport and I'm lucky to have two sets of fans that were very good.
"I'm pleased for that moment because I didn't get it at the end of last year. I'm very thankful for that."
City captain Vincent Kompany has no doubts his side can overcome the deficit, with 45 points to play for.
Kompany said: "That's probably the hardest away game we'll have this season. It gives us enough confidence to carry on and push for the league.
"Five points is not too much. Experience tells us that five points is nothing so for us it's time to start a good run again and to put everything behind and play at the level that we can again."
Chelsea took the lead four minutes before half-time through Loic Remy - who was deputising for the banned Diego Costa - only to see David Silva swiftly equalise.
The Blues, who were also without Cesc Fabregas (hamstring) and Filipe Luis (calf), could also be boosted by the imminent arrival of Juan Cuadrado from Fiorentina.