Gambhir (60) anchored the 152-run chase with his 47-ball knock as he and fellow opener Robin Uthappa (46) rattled up a 100-run stand, which paved the way for an easy win, which was 11th in a row for the IPL champions in this format.
The chase was complete in 19.3 overs as KKR lost five quick wickets after being placed comfortably at 113 for one at one stage.
Narine, in his excellent figures, took three wickets at the expense of just nine runs in his four overs as Lions posted 151 for seven after being asked to bat.
Narine scalped two batsmen in two balls in his three-wicket haul and it was largely the contributions from opener Ahmed Shehzad (59) and Umar Akmal (40) that propped up the Lions innings.
Gambhir and Uthappa stroked freely before off-spinner Adnand Rasool broke the stand by castling the latter in the 13th over. Exactly 12 balls later, Gambhir met the same fate at the hands of paceman Mustafa Iqbal.
KKR were firmly in control at that stage but lost wickets in a heap after that as they lost Manvinder Bisla (6), Yusuf Pathan (11), Ryan ten Doeschate (12) and Andre Russell (1).
Suryakumar Yadav (14) though ensured that KKR cross the finish line and there was no twist in the tale.
Gambhir was hardly troubled by any Lions bowlers as they bowled either full or short-pitched stuff at the Indian batsman, who got better and better with each stroke.
Gmabhir had no problem whatsoever as he and KKR were off to a flying start. The southpaw played ferocious cuts when challenged with short balls, lofted confidently on full length balls and dabbed elegantly as KKR raced to 48 in six overs.
Uthappa was dropped on 14 when the fielder failed to hold on to a difficult chance off paceman Cheema. This was after Uthappa drove Cheema for two boundaries.
Both the openers matched each other stroke for stroke as Pakistani side persisted with spinners, a strategy which backfired.
Uthappa lofted Mustafa Iqbal for a six and a four as KKR were placed comfortably and in control at 82 for none at half-way mark. He though encountered cramps in the middle of the 11th over and received treatment from physio.
Earlier, Lions opener Shehzad could have been stumped twice and also caught once before being finally dismissed. He ended up punishing the KKR bowlers with four sixes and five fours in his 42-ball knock.
Akmal scored 40 off just 24 balls before being dismissed off the last ball of the Lions innings. He creamed off 16 runs off Piyush Chawla in the 17th over, hitting the spinner for two fours and a six and also hit paceman Pat Cummis for a straight six in the last over.
Along with Wahab Riaz (14 not out) he added 48 runs for the seventh wicket in just 4.3 overs to help Lions recover some ground.
Akmal’s onslaught came after Narine dismissed Umar Siddiq (2) and Asif Raza (0) off successive balls. He could have taken a fourth wicket but dropped Wahab Riaz off his own bowling.
Australian paceman Cummins was hammered around when he bowled full as Pakistani batsmen were terrific in picking up the length after they being asked to bat.
Shehzad was comfortable swinging his bat on both sides as he found two boundaries, including a six.
Skipper Gambhir introduced Chawla in the fourth over but the leg spinner was also taken to cleaners by Shehzad even as the Indian bowler was unlucky as Manvinder Bisla missed an easy stumping in the fifth ball. Shehzad was on 19.
Debutant Kuldeep Yadav was impressive with his Chinaman stuff but he too was denied a wicket thanks to Bisla’s second miss. Again it was Shehzad who was the beneficiary. However, KKR finally got a wicket in the same over when Andre Russel’s direct hit found Nasir Jamshed (10) short of crease.
The KKR largesses for Shehzad continued as now Narine missed out on grabbing a catch chance at short third man when the batsman reverse swept.
Lions skipper Mohammed Hafeez (9) did not last long as he became the maiden wicket for young Yadav, who foxed the Pakistani batsman with a wrong one.
Shehzad completed his half-century with a cheeky boundary but was dismissed when caught at boundary ropes by Robin Uthappa off Chawla.
Kolkata Knight Riders: Gautam Gambhir(c), Robin Uthappa, Manish Pandey, Yusuf Pathan, Ryan ten Doeschate, Suryakumar Yadav, Andre Russell, Piyush Chawla, Sunil Narine, Vinay Kumar, Umesh Yadav, Kuldeep Yadav, Jacques Kallis, Pat Cummins, Manvinder Bisla(wk)
Lahore Lions: Ahmed Shehzad, Umar Siddiq, Nasir Jamshed, Mohammad Hafeez(c), Saad Nasim, Umar Akmal(wk), Wahab Riaz, Asif Raza, Imran Ali, Adnan Rasool, Aizaz Cheema, Mohammad Saeed, Ali Manzoor, Mustafa Iqbal, Agha Salman