Falcao’s consolation goal for the visitors came in added time after they hugely underperformed on the night.
Atletico’s poor away record continues to hinder them in their quest to stay ahead of rivals Real Madrid in the table, with the gap between the two sides now down to four points in the battle for second place.
Vallecano, meanwhile are back up to sixth and just two points adrift of Malaga in the fourth Champions League spot in La Liga.
Diego Simeone’s side knew it would be a tough match on the road again, even if they were only travelling across the capital to face their ‘little’ neighbours Rayo in their compact 15,000 capacity stadium. Europa League holders Atletico face FC Rubin Kazan in that competition on Thursday and they chose to rest the likes of Diego Godin and Arda Turan for this fixture, whilst striker Diego Costa was suspended after his yellow card last weekend against Betis.
Rayo responded brilliantly to their 2-1 defeat at Sevilla last weekend, that result having cost them a couple of places in the table. The home side stormed out of the blocks and were ahead in the opening minutes thanks to a close range finish from right winger Lass who gave Atletico’s Brazilian left back Filipe Luis a torrid time throughout the first half.
Indeed, the lead was deservedly doubled just after the half hour mark as Rayo’s Brazilian representative Leo Baptistão made the most of a low cross from the right by Lass, evading Filipe Luis and Cata Díaz to beat Thibaut Courtois at the near post.
It was perhaps telling that the last notable incident of the first half was a Falcao foul on Roberto Trashorras in midfield. There was no yellow card for the talented Colombian striker but the referee had to keep a close eye on things as Atletico were letting their tempers get the better of them at the end of that disappointing opening period.
Although Simeone sent on the highly rated Arda Turan at half time his side were unable to force a way back into the match after the break. They did show more attacking intent in the second half but were no huge threat to Rayo goalkeeper Ruben, who performed tidily when called into action as Falcao, Turan and Juanfran pushed forward.
Falcao’s late consolation came in the last of four additional minutes as he tapped in at the second attempt having tested Ruben with a header from a corner, but by then the visitors knew the game was up.
Rayo boss Paco Jémez had been sent to the stands before that, as he became over excited at the thought of a potentially historic win and began abusing the referee's assistants. Nonetheless his players held out for the three points and the home fans celebrated their first victory at home against their opponents from across the capital since January 1994.
Atletico have therefore not won an away fixture since 18th November when they beat Granada 1-0 and they have now gone eight games without a win in all competitions away from the Vicente Calderon stadium.