Lahiri, who carded an even par 71 on first day, turned in three-under 68 and at three-under 139. He is three shots behind co-leaders Miguel Tabuena (67-70) and Thaworn Wiratchant (70-67). Bangladesh pro Siddikur (70-68) is third.
Lahiri started with a bogey, but quickly recovered with birdies on sixth and ninth and turned in one-under. He birdied the 11th but bogeyed the 12th. He then birdied the 16th and 18th to finish at 68 for the day.
Meanwhile, three of the four Indians in the fray made the cut. Himmat Rai and Chiragh Kumar (76-72) made the cut, while Ajeetesh Sandhu (78-73) missed it.
Rai, the best Indian at 10th after first round, kept his position intact with a second round one-over 72 despite a poor run between third and seventh with two bogeys and a double bogey.
Rai was four-over after seven holes, before finding his way back with two birdies on eighth and ninth and then two more on 12th and 15th. He had another bogey on 11th.
Chiragh, who shot a disappointing 76 on first day, squeezed inside the cut line with a 72 and is lying 54th.
However, like Sandhu (78-73), Kunal Bhasin (75-75) also missed the cut. (MORE)