Suarez rescues Barcelona
The striker scored his second goal of the game in the dying minutes as Barcelona scored a smash-and grab win.
Rayo Vallecano might consider themselves unlucky not to take anything from the game, as they had led until the 87th minute, and showed spirit throughout.
The first chance of the match fell to the most in-form man on the field, Luis Suarez.
After a hat-trick against Real Madrid last weekend, it came as little surprise to anybody in the Estadio Vallecas that it was the Uruguayan who fired Barcelona in front.
After Ivan Rakitic sent Jordi Alba away with a stunning long pass, the left back had an age to pick out a target, and Suarez tucked away his cutback with ease.
However, despite Barcelona's dominance, their lead was soon to be cut short by Jose Pozo.
After the ball fell to him on the edge of the box, the Rayo midfielder sent a swerving strike into the net via the bottom of Marc-Andre Ter Stegen's left post.
The superb goal was made all the more unlikely given that Pozo had missed a sitter minutes earlier.
Luis Suarez almost scored his ninth goal of the season in the 40th minute when he curled a long-range strike off the post.
After the break it was Rayo who had the better of the play, with De Tomas being denied by a sprawling save from Ter Stegen in the 52nd minute.
The story of the match would get even better for Vallecano in the 57th minute, when substitute Alvaro Garcia fired them in front.
After De Tomas thumped the ball against the post from a near-post header, the ball fell perfectly to Garcia, who could only score from such a close distance. It was his first touch of the match.
Barcelona struggled to find their feet for much of the second half, looking the worse team for large spells.
However, at the death, Barcelona found a way to win. Their equaliser came from substitute Ousmane Dembele.
Gerard Pique's cushioned header from Jordi Alba's long ball set the ball up perfectly for the youngster, who fired in an excellent left-footed finish.
If that wasn't heartbreaking enough for the Rayo Vallecano fans, Luis Suarez killed off any hope of a point in the 90th minute.
From Sergi Roberto's long ball, the striker slid in at the back post to stab the ball home and win the game for the Blaugrana.
The result left Barcelona at the top of the table, while Rayo remained rooted in 19th.