Despite the Azzurri dominating proceedings early on, it was Spain who hit the front foot in the 14th minute when David Silva opened the scoring, before Jordi Alba raced out of defence and doubled their lead four minutes before the interval.
Italy were then reduced to ten men shortly after the hour mark after Thiago Motta, who had come on shortly before, limped off injured with coach Cesare Prandelli having used all his substitutes.
And the Spaniards made the most of their numerical advantage as they wrapped up the win with further goals in the final six minutes through substitutes Fernando Torres and Juan Mata.
In the process, Spain made history by becoming the first side to win three successive major international tournaments, with Del Bosque in charge for the last two, and speaking after the game, he credited Silva's opener with knocking the stuffing out of Italy and Alba's second with effectively deciding the result.
He told Telecinco: "They were trying really hard and the first goal wore them down. The second was definitive.
"We understand the joy of the people and we will celebrate the little happiness that we have given them."
It's true we were lucky enough to play a great match," said coach Vicente Del Bosque.
"Everything worked for us.
"It was an extraordinary performance against a difficult opponent."
Torres was largely responsible for doubling Spain's lead after coming on as a 75th-minute substitute, coolly finishing the third and then laying the ball off for Mata to make it four.
Del Bosque insisted that the Chelsea forward's cameo did not mean he was wrong to start three of the six games in the tournament without a recognised striker.
"We simply did what we believed was the right thing to do. We had a great a opponent in front of us and we were improving as a team," he said.
Alba, meanwhile, was delighted to cap his impressive performances throughout the tournament with his first international goal in the final.
"It was my first European Championship. They made history before and now I have done it with them. I still don't believe it but I will get used to it.
"Now I will enjoy it with the team. I have had a very good Euros and I have managed to score a goal. In these moments I want to thank my friends, my family and the people that have helped me so much."
The 23-year-old has also had a fine week off the field as his 14m euros transfer from Valencia to Barcelona was completed and he is looking forward to returning to the Catalan giants having come through the youth system there before being released at 16.
"I am very happy about signing for Barcelona. There has been an agreement between the clubs and at the end everything has gone well. I am so happy for everything that has happened."
Cesc Fabregas, who started in the most advanced role for Spain and set up the opener with a pinpoint cross, gave little quarter to his side's detractors.
The Spanish focus on possession football and closing their opponents out of the game has been branded as boring - though clearly effective - in some quarters.
That is not a view Fabregas has much time for.
Asked if tonight's [Sunday] performance was an answer for their critics, the midfielder told Radio Five Live: "I think so. Those people who think we are playing boring...in my opinion they don't understand the game.
"This feels really amazing, one of the best days of my life. I don't think we're ready to see what we have done. Three major trophies in a row has never been done before in the history of football.
"It's difficult to realise what we have done, but in time I think we will, It is amazing."
Watch: Spain beat Italy to Euro 2012 crown... More Videos
Andres Iniesta insists Spain must fully celebrate their achievement after they became the first side to retain the European Championship title.
The Barcelona midfielder was named man of the match as his side romped to a 4-0 win over Italy in last night's final in Kiev and hailed a truly historic achievement.
"This is something unique, magical and unrepeatable," he told AS. "We have to enjoy the moment."
Iniesta added: "The important thing is Spain are the champions which is what we came here for.
"It was a very complete game, we played very well with the ball and when Italy were left with 10 we pressured them very well.
"We played such a good all-round match which is what was demanded of us in this final."
European Championship Winners
1960 - USSR
1964 - Spain
1968 - Italy
1972 - West Germany
1976 - Czechoslovakia
1980 - West Germany
1984 - France
1988 - Holland
1992 - Denmark
1996 - Germany
2000 - France
2004 - Greece
2008 - Spain
2012 - Spain