Fernando Morientes put the home side ahead in the first half, but the English champions came back roaring with goals from Andriy Shevchenko and Essien in the second half.

We had to wait for the half hour mark to get some action.

Morientes started his show as he hammered the Chelsea goal with three attempts in just two minutes starting with a thumping effort off the right post.

The former Real Madrid striker found the target just a minute later when he fired home Joaquin's cross with a clinical left-footed finish.

The lively Morientes almost doubled the lead when he beat Petr Cech for the third time only to be denied by Ashley Cole's off-the-line clearance

Santiago Canizares produced a magnificent save to deny Didier Drogba's 40th minute superb header from the top corner.

Jose Mourinho started the second half with some tactical changes, bringing in Joe Cole for Lassana Diarra and sending Essien to the right-back position.

The move suddenly proved fruitful seven minutes into the second half, when the Valencia backline failed to deal with Essien's inviting cross and Shevchenko tapped in from point-blank range to level the score following a flock for the ball inside the Six yards.

Chelsea controlled large spells of the second half and they almost found the killer second goal five minutes from time when Michael Ballack's header was cruelly denied by 37-year-old Canizares.

However, the veteran keeper was stunned in the dying seconds when he was caught from a tight angle by a fierce strike from Essien whose move to right-back proved a masterstroke by Mourinho.

Chelsea will meet the winner from Wednesday's Liverpool and PSV game which is almost decided for the Reds' favor following their first-leg 3-0 win.