Chelsea failed in their attempt to become World club champions after an inept display against Brazilian side Corinthians.
The South American side looked like they wanted the game more than the Londoners.
However it was Guerrero in the 69th minute who scored the only goal of the match.
Quite what three chelsea players were doing sitting in the line and not one challenging the striker is anybodies guess.
Fernando Torres had the simplest of chances late on to level the score but failed the audition, kicking the ball straight at the goalkeeper Cassio when free in the six-yard box.
With both sides playing a 4-2-3-1 formations, the expected cat and mouse opening exchanges proved to be accurate.
Frank Lampard, now fit again and restored to the midfield showed his most expansive play, sending in Torres after 10 minutes. The Spain forward failed to test Alessandro.
However, from the resultant corner, Gary Cahill almost tucked the ball over the line through a melee of players.
Did the ball cross the line, no according to the new goal-line technology employed for the first time in this tournament.
The referee, Cüneyt Çakır of Turkey', signal in his ear to indicate the ball going over the line did not signal and so no goal given.
TV replays clearly confirmed that decision.
Juan Mata's wayward midfield pass on 17 minutes almost resulted in a goal for Corinthians but Luiz was able to shepherd Emerson and the ball away from goal.
The counter-attacking Brazilians, solid in defence, snowed their penetrating best, on 20 minutes but Paulinho's long-range effort sailed over Petr Cech's crossbar.
David Luiz had a fine chance to strike in goal from a free-kick, but his effort, just outside the Brazilian side's penalty area was woeful.
The ball was smacked into the wall and wishing six seconds was back in the Chelsea half as Emerson broke quickly. Thankfully for the Blues Luiz responded and got back to snuff out the counter-attack.
Guerrero fell easily in the penalty area after a Cahill challenge trying to sneak a penalty, but the ref waved play on.
Emerson flashed a chance over the bar after Cahill failed to intercept a Paulinho's pass on 28 minutes.
A brilliant cross field ball by Eden Hazard on 32 minutes bisected the Corinthian defence allowing Victor Moses to sneak in on the right . Bu the wide man could not get a shot away and was quickly hurried and the ball, went for a goal kick.
Guerrero turned the Chelsea back line a minute later sending the ball across to Emerson at the far post - but his left-footed effort smacked against Cech's right post.
Moses should have put the Londoners ahead with six minutes of the half to go. A quick counter saw the former Wigan winger, on the left, he produced an excellent curler but Cassio was equal to the task as he was again, two minutes later from a Mata long-range shot.
There were no changes at half-time from either side.
As for the game, very much the same as he first, defence on top with very little creative play in either last third.
Cassio smothered a Hazard shot after the Belgium broke through the Corinthians rearguard on 53 minutes as the Blues upped the tempo.
The first yellow card of the game went to Jorge Henrique on 55 minutes for bundling over Mata.
But it also signalled a change in pressure with the Brazilians taking control. They were unlucky not to get the opening goal on 62 minutes when Emerson fed the ball to Paulinho.
His drive from just inside the edge of the Chelsea area inched wide of Cech's left post.
But the inevitable happened on 69 minutes when Guerrero had the simplest of chances to head home.
The Brazilians produced a scintillating attack with deft one-touch football that pulled the Chelsea defence out of position.
Rafa Benitez response was what many were calling for since the first half, to bring in Oscar for the ineffectual Moses on 73 minutes.
Then he brought on right-back for right-back - Cesar Azpilicueta for Ivanovic with seven minutes to go.
Fernando Torres had the simplest of chances on the 86th minute when all he had to do was shoot either side of Cassio but somehow smacked the ball straight at the goalkeeper.
Marko Marin then brought on for Hazard.
To add insult to injury, Gary Cahill was brandished with a red card with a minute to go for an off-the-ball incident.
Torres thought he had score deep into injury time when he headed past Cassio, but he was offside.
With Corinthians sitting back, this allowed the Blues to pile forward but it was too little too late for the Champions of Europe.
Chelsea: 4-2-3-1 formation:
Petr Cech, Branislav Ivanovic, Gary Cahill, David Luiz, Ashley Cole, Ramires, Frank Lampard (c), Victor Moses, Juan Mata, Eden Hazard, Fernando Torres
Substitutes: Ross Turnbull, Hilario, Cesar Azpilicueta, Paulo Ferreira, Ryan Bertrand, George Saville, John Mikel Obi, Oscar, Marko Marin, Lucas Piazon.
Corinthians: 4-2-3-1 formation:
Cassio; Alessandro (c), Paulo Andre, Chicao, Fabio Santos; Paulinho, Ralf Danilo, J Henrique, Emerson; Guerrero.
Substitutes: J Cesar, F Danilo, Wallace, Martinez, Douglas, A Polga, W Arao, Edenilson, Guilherme, Felipe, Giovanni, Romarinho.
Referee Cüneyt Çakır of Turkey