After a cagey opening period, Spurs took the lead in the 19th minute through a brilliant Sandro effort.
Controlling the ball after Rafael van der Vaart's clever flick, the Brazilian midfielder unleashed a sensational 35-yard volley which left Petr Cech with no chance.
Tottenham controlled proceedings thereafter, but the Blues went into the break level thanks to a Heurelho Gomes howler combined with a linesman error.
Making use of the space afforded to him, Frank Lampard unleashed a speculative effort straight at Gomes, who somehow managed to let the ball slip under his body. Trying to make amends, the goalkeeper dived and successfully stopped the ball crossing the line, only for the linesman to give a goal.
After a second half that produced few clear opportunities, Kalou pounced to prod home amid suspicions of offside after Didier Drogba skewed a shot across the face of goal. The win moves Chelsea to within three points of Manchester United, who travel to Arsenal on Sunday.
Source: PA
Source: PA