Coach Mourinho's side dominated the first half-hour, with their counter-attacks carving apart a surprisingly open Galatasaray side, and took the lead through Fernando Torres.
But Galatasaray boss Roberto Mancini changed his tactics and saw his side draw level when defender Aurelien Chedjou took advantage of slack Chelsea defending at a corner. They were driven on by a raucous Turk Telecom Stadium crowd and Mourinho said: "This is Turkey, this is Istanbul, this is Galatasaray.
"The first half the game was our game, we had chances to win the game.
"I am not criticising my striker (Torres), my striker did a good game. We were just missing the last pass, the last touch, the last control.
"I can't complain, my players were fantastic. The second leg will be difficult, all I ask is that Stamford Bridge can give us 10 per cent of what this public gave to Galatasaray."
Lampard added: "We were disappointed at half-time we weren't more than 1-0 up because we played well, we controlled it.
"They didn't have many chances and we had four or five good counter-attacks and we're disappointed we didn't make more of them.
"Certainly the crowd (played a part), I don't know about the tactics because you always expect them to have a period, and they had a big period in the second half."
Former Blues striker Didier Drogba led the line for Mancini's side and threatened when his header flashed across goal and was volleyed against the post by Selcuk Inan.
The Ivory Coast international said: "It was a special game, to play against my old team-mates.
"I didn't get a lot of chances but the header was perfect – well, not perfect because I didn't score, but it was a great cross, I wish I could have scored this one but there is another game.
"It was a great game and I think it is a good result.
"Chelsea are the better team on paper but second half we showed we can create them some problems. Now we have to go out and do it at Stamford Bridge.
"They played on the counter-attack and we were a bit naive two or three times.
"We know they are dangerous, we have to work on that and solve these problems.
"If we manage to score a goal there, it's a different game. One-one is a good result."
Lampard was relieved his old pal Drogba didn't inflict damage.
"He is a great lad, it was an honour to play against him, and to play with him for years," he added.
"We'll have to watch him back at the Bridge."
Galatasaray boss Roberto Mancini says his side still have a fighting chance of making it to the quarter-finals.
"In the end it could be a good result, we should play like we did in the second half. We were too deep in the first half," said the former Manchester City boss.
"In every attack we lost four players during the first 20 minutes, they were counter-attacking us every time, and that's impossible against Chelsea.
"I brought off Izet Hajrovic, he didn't have a bad game, but we needed another midfielder. 1-1 is a good result and we have a chance."
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