كتب : Hatem Maher
Christian Schulz opened the score for Bremen in the first half before two strikes from Pavel Nedved and David Trezeguet late in the second period gave Juventus the lead.
Tim Borowski leveled the score three minutes from time before a last-gasp strike by Micoud sealed the victory for Bremen.
A draw in the return leg at the Delle Alpi Stadium would be enough to send Bremen through to the quarter-finals.
Schulz broke the deadlock in the 39th minute following a goal-mouth scramble when Fabio Cannavaro's clearance bounced off him and went into the back of the net.
Czech international Nedved put Juventus at level in the 73rd minute when he fired home from close-range after being fed by Patrick Vieira.
In-form Trezeguet grabbed the lead in the 82nd minute when Alessandro Del Piero's deflected pass went into the path of the Frenchman inside the area before heading the ball home.
Borowski equalized for the hosts in the 87th minute as he connected with Torsten Frings cross to send a near-post strike past Juve keeper Gianluigi Buffon.
Bremen playmaker Micoud secured the precious victory deep into injury time after he met Borowski's corner with a deft header into the back of the net.