The world and European champions needed a 64th-minute Cesc Fabregas leveller to rescue a point in the Polish port city of Gdansk on Sunday after substitute Antonio Di Natale had fired the Italians ahead four minutes earlier.
Del Bosque left Fernando Torres and his other two centre forwards, Fernando Llorente and Alvaro Negredo, out of his starting lineup, opting instead for an attacking line featuring a roving Fabregas and Andres Iniesta and David Silva.
Del Bosque said one of the aims of his formation had been to give Spain more security in possession but they struggled to get their swift passing game going on a dry and heavy-looking pitch against a well-drilled Italian side.
Iniesta caused problems with his darting runs in from the left and forced Gianluigi Buffon into several smart saves, while Silva had a quiet game by his standards - although he did provide the assist for the goal - before he was replaced just past the hour mark by winger Jesus Navas.
When Torres came on for the last 15 minutes as a tight game began to open up he fluffed two scoring chances when he was through on goal with only Buffon to beat.
"We have a lot of confidence in what we did," Del Bosque said on Spanish radio station Cadena Ser. "We have three fantastic forwards but Cesc is also a good forward."
"He has a lot of composure on the ball, he links up well with everyone and he gets into good scoring positions.
"We did what we thought was best even if we risked being mistaken. We have players who are very difficult to control and I thought it was the right time to do it."
Del Bosque's tactics drew criticism from his predecessor Luis Aragones, who was Spain coach when they won the continental title four years ago.
In a guest column for Marca sports daily on Monday, Aragones said the decision to deploy Fabregas as what he called a "false centre forward" had surprised him.
"Obviously, I respect the coach's decision but I would have played with a centre forward," wrote Aragones, known as "the wise man of Hortaleza" after the Madrid suburb he comes from.
"In the second half Torres ... found space and caused a lot of damage," he added.
Spain meet Ireland on Thursday after Giovanni Trapattoni's side were thumped 3-1 by Croatia on Sunday and Del Bosque said he may start without a striker again.
"It's possible we'll play the same way," he told Cadena Ser.
"I don't rule out putting someone up front but (playing without a striker) is an option we have," he added.
"I believe they are good players to do it, Silva, Fabregas and Iniesta, and I believe they are forwards.
"Matches are usually different in the second half, when the game opens up.
"In the first half teams tend to be better organised and there are fewer chances for counter attacks.
"We made the most of the space (when Torres came on) but unfortunately we were unable to take our chances."