Barcelona - Neither claimed a clear advantage but Barcelona and Real Madrid each had cause for optimism following a frantic 1-1 draw in the first leg of their Copa del Rey semi-final.
"The result does not point to any clear favorite," Barca coach Ernesto Valverde said after Wednesday's match.
"The tie is open," said Madrid's Santiago Solari. "Anything can happen."
Barcelona will have Lionel Messi available again for the return on February 27, after their captain was deemed fit enough only for 27 minutes of a compelling opener at Camp Nou.
The thigh strain he sustained against Valencia last weekend is considered minor, with Valverde hopeful he will be able to start against Athletic Bilbao on Sunday.
"If he is okay to play, he will but if he is not right, he won't," Valverde said. "But we hope he will be fine."
Ousmane Dembele could also be back at San Mames and, along with Messi, the duo's availability for the first of two Clasicos in four days at the end of the month would certainly make Barcelona stronger.
They were sloppy for the best part of half an hour on Wednesday and Madrid might have taken the tie away from them had Vinicius Junior and Karim Benzema shown the same precision as Lucas Vazquez, who had nipped in at the front post in the sixth minute.
Instead, Barca kept the deficit to one and then took hold of the contest, their midfield seizing control before a nervy last 10 minutes.
The only surprise was that Malcom's equaliser shortly before the hour had not come sooner but Valverde's side saved their best for the second leg in each of the previous rounds, and he will feel they are well-placed.
"The season is long," Gerard Pique said. "We will try to win the second leg but there are many competitions before then and the league and Champions League are more important. We will try to reach the final."
Madrid will take heart too, from a purposeful early spell that rattled Barcelona and then an extended show of resilience, the kind that was absent in their 5-1 hammering on the same turf in October.
"Comparisons are unhelpful," said Solari. "But it shows how hard the team have worked."
A draw feels a long way off revenge but there was a measure of redemption at least for a side who can tag this result onto six victories in eight games, the only blemish a second leg defeat to Leganes in the quarter-finals, when the tie was already all-but won.
With an away goal secured and home advantage to come at the Santiago Bernabeu, Madrid's only regret might be that they could not snatch a victory when the ball fell to Gareth Bale in the dying minutes.
Marc-Andre ter Stegen was out of position but Bale's shot was blocked by Nelson Semedo, a missed chance for the Welshman, who had been left out of the starting line-up, demoted behind Vazquez and Vinicius.
"We had chances to score a second goal but we leave satisfied with what we did," Solari said.
Bale is still regaining sharpness after three weeks out with a calf injury but the brilliant form of Vinicius and the loyalty Vazquez enjoys from Solari means he cannot take his place for granted.
"Lucas has the virtues that I value most in the Spanish character," Solari said. "He has solidarity and he is brave."
Real face Atletico Madrid on Saturday in La Liga, when a win would see them jump above their city rivals into second in the table. Their resurgence remains on track.