A pulsating 223rd Clasico clash ended all square for the 48th time, leaving Real Madrid one ahead of Barcelona at 88-87 in official games and with everything to play for in next month's return at Camp Nou.
Cesc Fabregas gave Barcelona a second-half lead, calmly scoring past Diego Lopez when left with too much time on his hands.
But Raphael Varane had the final word, capping his impressive performance with a late header to level the score.
The match was not without its little fascinations and complex storylines though, as the following slides reveal.
With injuries to Iker Casillas and Pepe, Marcelo not deemed fit enough to start and Sergio Ramos and Fabio Coentrao suspended, Real Madrid's back four featured only one regular starter—Alvaro Arbeloa.
Centrally they lined up with two players at different ends of their careers in Raphael Varane and Ricardo Carvalho, while midfielder Michael Essien filled in at right-back.
The French youngster Varane shone brightest even before his late header kept the tie in the balance.
His late second-half tackle on Messi was as adept as a similar one he made in the first half. While Carvalho at times looked a walking red card—his dodgy back pass was not punished thanks to Varane's goal-line clearance—the 19-year-old was under control.
Stand-in boss Jordi Roura had the luxury of fielding a full-strength XI at the Bernabeu on Wednesday but will be ruing a chance missed as the game remains in the balance ahead of the return leg at Camp Nou at the end of February.
Andres Iniesta continued to be deployed on the left of the front three with Javier Mascherano missing out in favor of Gerard Pique and Carles Puyol.
But with Cesc Fabregas, Dani Alves and Pedro Rodriguez all missing chances at 1-0 and Xavi hitting the bar and seeing an effort cleared off the line at 0-0, La Blaugrana will have been disappointed to draw.
Only at the Camp Nou in a month's time will we find out if they will live to regret Wednesday's missed chances.
With Wednesday's draw, Barcelona extended their extraordinary run at the Santiago Bernabeu to just one defeat in their last nine visits.
That defeat was in August in the Spanish Super Copa.
Wednesday's result came in spite of some fairly cynical breaking up of play from Real Madrid, particularly Xabi Alonso.
Although the stats reveal three yellow cards for each side, the foul count ended at 19 by Real Madrid compared with just three by Barcelona.
Iker Casillas hasn't missed an El Clasico fixture since 2002, but his injury left him unavailable on Wednesday.
Into the fray came new signing Diego Lopez—all 6'5" of him. Jose Mourinho preferred him over Casillas' understudy Antonio Adan, which makes interesting reading into the mind of Madrid's boss.
The Portuguese coach was proved right, though. Some fine saves from the former Villarreal and Sevilla stopper arguably kept Los Blancos in the match.
One from Dani Alves and another at the feet of Lionel Messi were the pick of the bunch.
Around this time last year, Barcelona traveled to AC Milan for a Champions League game.
Gerard Pique was a long way from his best, and the Catalan press were citing various reasons for what they thought the problem was.
Whatever the reasons, Pep Guardiola took the decision to leave him out on a number of high-profile occasions.
Pique returned to form at Euro 2012 and has established himself as Barca's No.1 centre-back this season.
His performance against Real Madrid was an example why he's the top centre-back. His sliding interception to prevent a Cristiano Ronaldo equalizer was a particular highlight.
Before kickoff, Lionel Messi had registered 43 goals in 29 Barcelona appearances.
On Wednesday, he failed to score at the Bernabeu in the Copa del Rey, lengthening his dry spell against Real Madrid in Copa games to four appearances.
Had he scored he would have collected 18 El Clasico goals—level with Alfredo Di Stefano in the history of the fixture.
As it is, Di Stefano remains top dog a little longer, although two more Clasico matches are not far away.