Although defending champion Manchester United can stay level on points with its local rival with victory over Swansea in Sunday's late match, City's superior goal difference means that it will almost certainly win the title if it beats struggling Queens Park Rangers in its final match next weekend.
United is at Sunderland in the final round next Sunday.
"It's not finished," Toure said. "We have one game left and we have to be careful as QPR are fighting to stay in the Premier League. We have to continue to work hard and believe.
"This is brilliant for us, though."
Tottenham kept fourth place from Newcastle with a 1-1 draw against Aston Villa, while Clint Dempsey scored his 50th Premier League goal to help Fulham to a 2-1 win over Sunderland.
Djibril Cisse scored in the 89th to give QPR a 1-0 win over Stoke and move his side two points clear of the relegation zone, while Bolton missed the chance to climb out of the bottom three when it let slip a 2-0 lead and drew 2-2 with West Bromwich Albion.
Relegated Wolverhampton Wanderers drew 0-0 with Everton in the other match.
With both City and Newcastle needing victory — one for the title chase and one for its top-four challenge — there were chances at each end before Toure's goals.
City goalkeeper Joe Hart made a reflex save from Hatem Ben Arfa's fierce volley in the 34th after Demba Ba's shot had been blocked. Seven minutes later, Gareth Barry's low drive was blocked by defender Fabricio Coloccini and his rebound effort was stopped on the line by Davide Santon.
Barry then tried a third shot but Newcastle and goalkeeper Tim Krul managed to clear.
Toure made the breakthrough in the 70th, exchanging passes with Sergio Aguero on the edge of the area and placing a curling right-foot shot past the diving Krul.
The Ivory Coast midfielder then missed a clear opening — slipping as he tried to take the ball around Krul — before making it 2-0 as City exploited space left by the home side's search for an equalizer.
Tottenham was unable to take advantage of third-place Arsenal's 3-3 draw against Norwich on Saturday. Ciaran Clark put struggling Villa ahead in the 35th and Spurs had fullback Danny Rose sent off shortly after halftime for a foul on Alan Hutton.
Spurs only equalized in the 62nd after Villa defender Richard Dunne brought down Sandro in the area, allowing Emmanuel Adebayor to dispatch the resulting penalty for his 16th league goal of the season.
Tottenham has 66 points to Arsenal's 67 and Newcastle's 65.
American forward Dempsey scored his 17th Premier League goal this season with a 12th-minute free kick at Craven Cottage. Defender Philip Bardsley levelled for Sunderland in the 34th with a shot from the edge of the area but Mousa Dembele restored Fulham's lead just a minute later with a deflected drive which found the top corner.
Fulham's fifth win in seven games give the west London side with a chance of matching its best ever position of seventh if it wins at Tottenham next weekend. Currently eighth, Fulham is a point behind Everton.
With Wolves already relegated, Blackburn and Bolton are the other sides in the three-team relegation zone. Blackburn plays Monday against Wigan, which is level on points and goal difference with QPR.