Scotland's win was by a record margin against the Welsh as they ran in five tries, with Russell directly involved in three of those. He now has 10 try assists in nine matches since the start of 2022, more than any other player from a tier 1 nation.
But despite Russell running the show in attack, Townsend believes it was his defensive effort that was most pleasing.
"Perhaps the most impressive part of his game was his defence. Wales ran down his channel but he made tackle after tackle. So to then have the accuracy he showed in attack after that shows what a competitive player he is," Townsend told the BBC.
"The players outside him then give him so many options. It was a collective effort and, with Finn in that form, it was very good."
Townsend was less impressed with his side’s first-half display in which Wales enjoyed 70% possession, though the Scots still led 13-7 at the break.
"The first half, we didn't get our game going. We didn't get through the first two phases on enough occasions. Wales were competing hard at the breakdown, slowing our ball down or winning the ball back," Townsend said.
"But we did build a score which was pleasing. Second half was much better, our contact work improved, our maul was really strong which brought penalties and narrowed up the defence. Our backs were making the right decisions and getting behind the defence.
"We're up against a top team who will stop you from playing but we looked at ourselves - how we could get support to the ball carrier better, how we could finish off a couple of opportunities.
"On the flip side, the second half we were getting the opportunities and they lead to tries. That's an outstanding win for the group because Wales have been a top team for a number of years. To come away with any win is pleasing, one with a bonus point sets us up well."
Scotland have 10 points from their first two Six Nations matches and are behind leaders Ireland in the table on points difference. They visit France in their next game on February 26.
