Kevin Davies grabbed a second-half equaliser as Bolton left Chelsea's title chances hanging by a thread.
Davies nodded in Gary Speed's free-kick to allow Manchester United to stretch their Premiership lead to five points thanks to their superb win at Everton.
Lubomir Michalik fired Bolton ahead from close in but Salomon Kalou's fine header quickly drew Chelsea level.
The Blues went ahead when Kalou's powerful header came back off the bar, hit Jussi Jaaskelainen, and went in.
Bolton boss Sam Allardyce feared his makeshift line-up - missing six regulars and forcing him to play Ivan Campo at right-back - would struggle to contain Chelsea.
And their chances of a dull, battling draw looked slim after a frantic opening, which saw Chelsea on top.
606: DEBATE
But despite their injury problems and the speculation that boss Allardyce is likely to be quitting in the summer, the away side settled and took the lead after 18 minutes.
Nicolas Anelka had already blazed high and wide when he should have scored but when a Campo free-kick caused confusion in the home defence, the ball fell invitingly to giant centre-half Michalik who kept his composure to shoot home from six yards.
Chelsea's response was immediate. The impressive Wayne Bridge steamed forward on the left flank and his delightful cross was met by Kalou at the near post and expertly flicked into the far corner.
Ricardo Carvalho was then forced off with a knee injury that rules him out of Tuesday's Champions League game against Liverpool.
Chelsea boss Jose Mourinho had chosen to rest Frank Lampard, Didier Drogba and Joe Cole but Carvalho's injury saw Lampard come on and Essien revert to centre-half.
But the change did not affect Chelsea's attacking prowess.
Jaaskelainen made a fine stop to deny Andriy Shevchenko - who had earlier wasted a great early chance to put Chelsea in front - and Essien snatched a shot wide after the Bolton keeper missed a Lampard corner.
The pressure told when Kalou put the Blues ahead at half-time when he leapt to head home another Lampard corner, the ball bouncing down off the bar and hitting Jaaskelianen before going over the line.
But Bolton levelled within nine minutes of the restart.
Speed's free-kick saw Davies pull away from his marker Essien and the big striker rose unchallenged to head home from in front of Petr Cech.
Didier Drogba, on as a half-time substitute for Shevchenko, flashed a cross across goal and a vicious Lampard free-kick went narrowly wide.
Joe Cole soon followed Drogba and Lampard into the action but to no avail.
Bolton, recognising they were struggling to hold out, took every opportunity to attack and Andranik Teymourian flashed an effort inches over from 25 yards.
Abdoulaye Meite was fortunate to get away with a blatant handball on the edge of the area but Chelsea were unable to force a winner.
Chelsea: Cech, Geremi, Carvalho (Lampard 29), Terry, Bridge, Diarra (Joe Cole 60), Mikel, Essien, Wright-Phillips, Kalou, Shevchenko (Drogba 46).
Subs Not Used: Cudicini, Boulahrouz.
Goals: Kalou 22, Jaaskelainen 34 og.
Bolton: Jaaskelainen, Campo, Meite, Michalik, Gardner, Teymourian, Thompson (Vaz Te 46), Tal (Sinclair 77), Speed, Davies, Anelka (Martin 90).
Subs Not Used: Al Habsi, Augustyn.
Booked: Gardner, Davies, Michalik.
Goals: Michalik 19, Davies 54.
Att: 41,105.
Ref: R Styles (Hampshire).