Trailing 16-9 at the break, Glasgow were energised by the arrivals of Josh Strauss, Dougie Hall, Leone Nakarawa and Moray Low in the second half, all of whom were to make significant contributions to an impressive pack performance that starved Edinburgh of possession after the interval.
"We had not defended very well early in the game and we had not been ambitious or accurate enough in attack," said Townsend. "Later, I thought we played really well. The bench did very well. A pitch like that takes a lot out of you, and the way Edinburgh play takes a lot out of you as well, because they go phase after phase.
"So we used our bench, some for injuries and some for freshness. So much effort goes into the way Edinburgh play. It is tiring going through 20-odd phases. It's tiring to defend it but it must be tiring to go through all those rucks as well."
Townsend suggested that Stuart Hogg - who scored the winning try - had been an injury doubt for the game, but refused to reveal why the Scotland man's place in the starting XV had been in jeopardy. Instead, he praised Hogg's overall sharpness, in defence as much as for how he took his 68th-minute score.
After a run of home defeats, Townsend admitted that his side had underperformed in the first half and that the game's backdrop had contributed to their display. "At the beginning you could tell that Edinburgh were confident and knew what they wanted to do," he explained. "I thought we got caught up in the emotion of the derby, with guys trying to fly up out of defence, tackle on their own and getting bumped off. It just took some time to get into a rhythm, but a win gives you a nice boost and a nice feeling for the next few days."
Alan Solomons, the Edinburgh coach, pinned his team's defeat on their lacklustre performance in contact in the second period. "I don't think fatigue was a factor," said the South African. "I think the breakdown was a key area. I've got to have a close look at that, look at the video very carefully to see what went on there."
He highlighted one particular incident that he felt had cost them the match. "I always thought it would be close," he said. "We were leading and had just made good yardage when our stand-off Greig Tonks unfortunately had the ball ripped from him and that led to the try. Apart from that they didn't look like scoring the try.
"But that's how [results in] derbies happen, often they turn on one particular incident. That's the difference."
Solomons also rued another potentially key incident: "Cornell Du Preez was two metres from the line in the second half and just couldn't get over. I felt we did enough on the day to get the win."