Nikolai Zherdev and Fredrik Modin scored goals to help the Blue Jackets end a four-game losing skid and extend the Kings' winless streak to four.
Leclaire was the Blue Jackets' first pick - and the eighth pick overall - in the 2001 draft. He shared the job a year ago before Columbus traded Marc Denis to Tampa Bay for Modin and backup goalie Fredrik Norrena on June 30.
For the most part, the Kings set the tempo and controlled the puck throughout the game but failed to score on eight power plays. They outshot the Blue Jackets 38-14. It was the second-fewest shots Columbus has ever had in a win.
Seconds after the Kings' Anze Kopitar lost the puck on a backhand with a wide-open net in front of him late in the first period, the Blue Jackets broke through.
Rick Nash dug the puck off the short boards and tossed a long pass that found Zherdev skating clear of the defence. Zherdev deked to the forehand side then went to the backhand and chipped the puck high into the net over goalie Dan Cloutier's right shoulder for his fourth goal.
The Kings were ineffective on seven consecutive chances with a man advantage from early in the first period through the first two minutes of the third period.
Leclaire also turned aside the Kings during 50 seconds of 5-on-3 midway through the second period. He twice stopped Rob Blake on slap shots during the two-man advantage.
At the 8:15 mark of the third, Modin carried the puck behind the net and then fed David Vyborny, who passed back to Modin for a one-timer from the right circle. It was Modin's second goal of the year.
The Kings have scored one or fewer goals in seven of their last nine games. They had 11 goals in the first three games, 12 in the nine games since.
Notes: RW Dan Fritsche returned to the ice for Columbus after missing four games with a shoulder injury. ... The Kings are 10-8-1-2 in the series with the Blue Jackets. ... Nash had been scoreless in his last four games before assisting on the opening goal. ... Columbus had also lost its last two games at Nationwide Arena.