Chelsea coach Thomas Tuchel rued his side's missed chances after dominating Real Madrid in the first leg of their Champions League semi-final.
A goal from USA international Christian Pulisic fired Chelsea inside a quarter-of-an-hour at the Alfredo di Stefano Stadium, and the visitors created plenty more opportunities to put the tie beyond their hosts as Real failed to trouble Edouard Mendy at the other end.
Yet Chelsea's inability to score a second away goal proved costly as Karim Benzema's fine effort levelled things up before the break with his side's only shot on target in the opening period.
"I have a feeling we should have won the first half and we could have perhaps decided this game in the first half an hour when we were playing so strong," Tuchel told the BBC.
"The second half was a tactical game and you could feel we only had two days in between two away games which made it physically and mentally demanding and you could feel it in the decision making.
"We suffered a bit and an extra day would have been nice."
Timo Werner failed to beat Thibaut Courtois from close range early in the game and Tuchel was left frustrated by the German striker's inability to put away clear chances.
"He missed a big one at West Ham United [on Saturday] and now he's missed a big one here, that doesn't help," Tuchel told a news conference. "It doesn't help crying about it or regretting it.
"There are millions of people who have harder things to deal with than chances that you miss ... I don't feel we're pointing fingers but of course the strikers want to score.
"This is the highest level and when you have a good half-an-hour like we did ... then yes we wish for more composure and more precision in the decision making and finishing."
Despite failing to inflict more damage on Madrid, Chelsea are in the driving seat to reach a first Champions League final since 2012 ahead of next week's return leg at Stamford Bridge.
Real had breezed past Liverpool and Atalanta in their last two home knockout games but were really put to the test by Chelsea's intense pressing game and Zidane credited Tuchel's side for keeping his team at bay.
"We are good at pressing teams high up the pitch but our opponents were very good, very competitive. They've had 21 games and not conceded in 16 of them [before Tuesday's game] and they proved why. They are in the semi-finals for a reason," he added.
Real keeper Courtois agreed that the Premier League outfit had been the more impressive side but warned that his team would put them under pressure in the second leg in London.
"They were more aggressive and more intense, we wanted to start the game like they did, they gave everything. The first goal came at a difficult time for us but we were able to lift ourselves up and the second half was less crazy," he said.
"The 1-1 score means next week's game is like a final. I don't think it will end 0-0 and if Chelsea sit and wait for us they could be making a big mistake."