He and partner Jan-Lennard Struff were beaten 6-2 3-6 7-6 in their first round doubles match against Radu Albot and Malek Jaziri at the Australian Open last night.
A last set tiebreak went back and forward as neither pair could pull away, before two unforced errors handed Albot/Jaziri an 11-9 win.
The loss comes after winning last weekend's ASB Classic in Auckland and making the semifinals at last year's Australian Open.
It was a horror start for the eighth-seeded McLachlan/Struff, who were broken on the third game of the first set.
That left them trailing and while they fought back to 3-2, Albot/Jaziri held serve after McLachlan/Struff threatened to break back.
Albot/Jaziri made it 5-2 shortly after, taking the game to deuce and claiming the break on a double fault.
They held serve to win the set.
McLachlan/Struff came back in the second set, leading 3-2, before emerging from a long deuce to break and go up 4-2.
It was the decisive game in the set, as the pair held their next two serves and took a 6-3 win.
There was nothing between the two sides in the third set.
Neither could force a break and were forced to a tiebreak at 6-6.
That closeness continued through the tiebreak, both sides leading at different stages but never able to get the two-point advantage needed.
It was Albot/Jaziri that held out long enough to claim the win.
