Gerard Pique revealed his relief after he struck late to start Spain's European Championship defence with a victory.
The defender's 87th-minute strike sealed a 1-0 win over the Czech Republic on Monday, putting them joint top of Group D with Croatia.
Spain dominated but had to wait until Pique nodded in Andres Iniesta's cross with three minutes left to finally beat goalkeeper Petr Cech in their opening Euro 2016 game in Toulouse.
The Barcelona centre-back told Spanish TV channel Telecinco: "We played really well, controlled the game, made lots of chances, but the ball did not want to go in.
"I had the fortune to score the goal, but the team all played very well. We attacked with a lot of order, opened up the field well, and had to keep attacking until the goal came.
"It was a great ball from Iniesta. We wanted to win as we knew it was very important to get three points in our first game. Now we will wait on the second game."
Pique scored four goals in his first 12 Spain outings but his late header was his first goal for his country in 66 matches.
Cech also made more passes in this game than any other Czech Republic player (36) to underline Spain's dominance.
The Arsenal keeper twice denied Alvaro Morata and saved from Jordi Alba and David Silva while Roman Hubnik almost scored an own goal when his clearance hit a post.
Man of the match Iniesta also insisted Spain will not ditch their possession-based style, which saw them win the last two European Championships and the 2010 World Cup, despite almost failing to win.
"This is our path," he told Telecinco. "We have achieved many successes doing this. It is our way. We have a very good team, can overcome any rival, although it is always difficult. This win will keep us relaxed, these are an important three points, and now we will keep going.
"We have played many games like this before. We try and push and push and push, so that the defence makes a mistake in the end and we can score.
"Football is like this, sometimes you have the ball a lot, and in the end the game tilted our way and we are very happy."
Boss Vicente Del Bosque added: "We have started the finals well. Three very important points. We are still in charge of our own destiny. It was a great result for us. We had the initiative for most of the game, apart from a few moments, so it was strange we had to wait so long for the goal."
The Czech Republic could still have snatched a point in injury time but Vladimir Darida's volley flew straight at David De Gea.
Manager Pavel Vrba told a press conference: "It's disappointing to concede a goal so late. We could have scored ourselves, which doesn't often happen against Spain.
"We played at our maximum level and it is a shame not to get at least a point."
Cech added to UEFA.com "I thought we did exceptionally well for 86 minutes, we were constantly under pressure but we managed to work them. Unfortunately their talent and quality is huge and they managed to find the goal."