Chelsea 3 // Birmingham 1
Carlo Ancelotti's decision to leave out Fernando Torres paid off as Florent Malouda and Salomon Kalou fire Chelsea up to second in the Premier League.
The champions beat Birmingham to become Manchester United's closest challengers, moving to within six points of the leaders and giving themselves a glimmer of hope of retaining their crown.
Once again looking far more comfortable in their tried-and-trusted 4-3-3 formation, Malouda and Kalou scored impressive first-half goals and the former struck again before Sebastian Larsson netted a consolation from the penalty spot.
Torres' omission was significant as it was the first time he had been left out of the XI for two successive games, with Ancelotti appearing to acknowledge Didier Drogba was in far better form.
Chelsea were facing an in-form Birmingham side who had taken seven points from nine to ease away from the relegation zone.
But they were behind inside three minutes to a super goal, John Terry spraying the ball wide to Paulo Ferreira, whose cross was flicked on by Drogba for Malouda to crash home.
Chelsea were rampant and Drogba's 25-yard curler was almost fumbled into his own net by Ben Foster.
Terry's mistake let in Hleb but the Chelsea captain recovered to make the tackle.
Drogba was full of confidence, trying to chip Foster from 35 yards midway through the half.
Salomon Kalou was also not afraid to try his luck and produced a magnificent second goal, turning away from Roger Johnson, side-stepping Stuart Parnaby and unleashing an unstoppable 20-yard shot into the corner of Foster's net.
Hleb, recalled despite saying he did not want to stay at Birmingham when his loan expires, teed up another chance for Jerome but the striker's shot on the turn was blocked by Ashley Cole.
Kalou nodded over the bar, Foster saved Lampard's tame effort and Michael Essien hooked wide as Chelsea finished the half on top.
Parnaby earned the game's first booking for bringing down Kalou shortly after the restart, with Essien seeing his header from Drogba's resulting free kick deflected behind.
Chelsea began to get sloppy and Johnson headed a corner just wide before Cole was replaced by Ryan Bertrand, the 21-year-old finally earning his debut after a career spent out on loan.
Bertrand took less than six minutes to make an impact, Malouda rising to head home his 62nd-minute cross unchallenged.
Birmingham were reeling and sublime skill from Drogba almost set up Essien for number four.
Torres had been warming up in the meantime and, with the game won, he and Nicolas Anelka made their entrance in the 67th minute, replacing Malouda and Kalou.
The remainder of the game became about whether Torres could end his 870-minute goal drought for club and country, 701 of them in a Chelsea shirt.
Three minutes later, Birmingham withdrew Jerome and Hleb for David Bentley and Matt Derbyshire.
