Sandro was outstanding in Spurs' 0-0 draw with AC Milan on Wednesday night.
And Townsend wrote in his column for the Daily Mail: "On Wednesday he came of age. His positioning and sense of danger were so impressive — I’ve seen experienced defenders lacking that awareness.
"He sat in front of Michael Dawson and William Gallas to cut out the final pass into Pato and Robinho and he did it to great effect, making vital interceptions and always staying on his feet in the tackle.
"He understood the role he was meant to play and carried it out well. He didn’t vacate that middle of the park, even though the Milan full backs were pushing high up the pitch, which gave their midfielders a lot of possession."