Mexico dominated the first half and scored a fine goal through striker Oribe Peralta in the 17th minute, but substitute Robbie Rogers netted the equalizer in the 73rd minute for Klinsmann's new-look U.S. side.
Far from the wide-open 4-2 loss to Mexico in last month's CONCACAF Gold Cup final, the U.S. struggled to get possession, while their opponents failed to create many scoring chances.
Mexico seized the initiative when Andres Guardado drove in a cross from the right and Peralta volleyed home on the turn.
The first U.S. effort on goal finally came in the 56th minute with a powerful header from captain Carlos Bocanegra from a corner which was parried out by Mexico keeper Guillermo Ochoa.
Klinsmann, who replaced the sacked Bob Bradley, brought on Rogers and fellow substitutes Brek Shea and Juan Agudelo and they all combined for the equalizer.
Agudelo found Shea who burst into the area and slipped a low pass across goal to the unmarked Rogers who tapped home.
"We felt that it was coming, we put more pressure on them and could feel something was coming and it came at the right time," said Klinsmann.
"They are one of the top 10 teams in the world and with very good individual players and it took us time to get into the game. We tried to pass from the back and that is pretty complicated against Mexico but we had the confidence to do that.
"In the last half hour it was really our time to get them into trouble," added Klinsmann, who clearly enjoyed his return to the bench for the first time since he was sacked by Bayern Munich in 2009.
"I had a lot of fun, a lot of fun with the coaching staff and players and felt the energy out there and the fans really got into the game. It was a really nice feeling," said the 47-year-old.
The U.S.'s next friendly games are against Costa Rica on September 2 in Los Angeles and away to Belgium four days later.
