4-6, 6-4 in three hours and 11 minutes of match time, although rain halted the match for more than four hours after he won the third set.
"Bummer for me, momentum switch," Devvarman said. "But you have to pull your pants up and deal with it. Just the nature of the beast."
Devvarman made 36 unforced errors, fewer than half of Lacko's 73 such mistakes, and hung tough at the finish
"When you are playing in the fifth set, a lot of it is you play with adrenaline at that point. I know both of us were dying at the end," Devvarman said.
"I was pretty antsy and he was too. The nervous energy affected the both of us. We were just trying to do our best."
Devvarman had just battled back to secure the third set when showers began to fall, sending him into the locker room. After a tease of returning quicker, more rain left him to sit and the marathon wait continue.
"I got two quarters of a meal at different times," Devvarman said. "You just take a shower, eat and try to relax. You are in there with a bunch of your friends, playing games and the time passes pretty quickly."
So did his momentum.
"Stopping and starting, it was a little unlucky to stop there," he said. "You can't control the weather. It changed the momentum. He came out and played well, changed his tactics. He played a great fourth and fifth sets."
But at 4-4 in the final set, Devvarman came through with a break and held to book a second-round date with Italian 20th seed Andreas Seppi.
"I'm very happy with the way I played. It was an incredibly tough match," Devvarman said. "I played a few great scramble points there in the fifth set at 4-4. I'm happy with that last bit of effort out there."
Devvarman said having to fight through three qualifying matches has been an advantage.
"Less time on the court is better but you do what you can to take advantage of what you have," Devvarman said. "I'm familiar with the speed of the courts. I've played a lot of matches.
"I'm match sharp. I hope I can take advantage of that in the next match. The only way I can improve is to fight through every match and I feel like I've done that."