Mauricio Pochettino says Heung-Min Son is "on fire" after the forward scored the winner in Tottenham's 1-0 victory over CSKA Moscow in the Champions League.
Spurs dominated possession and had 22 shots in the newly-built Arena CSKA but in the end it was only Son's 71st-minute strike that secured the visitors a crucial three points.
The South Korean has now scored five goals in as many games this season, and three in his last two, an impressive return for a player that was almost sold in the summer, one year after arriving from Bayer Leverkusen.
Son's form has also minimised the impact felt by the loss of Harry Kane, who remains out with an ankle ligament injury and could be set for at least another month on the sidelines.
"I think it is key," Pochettino said of Son's recent success. "It is very important that not only Harry, who was good before his injury and scored, that now another player has scored and that is very important for the team.
"I feel very pleased for Sonny. He is on fire and to keep this form is very important for us."
Son started on the left of an attacking three but was pushed into a central role up front in the second half, as Pochettino made the bold move of replacing striker Vincent Janssen with the pace of winger Georges-Kevin N'Koudou.
The change worked, as five minutes later Erik Lamela slid through Son and he poked the ball under Igor Akinfeev to finally break the deadlock.
"We tried to find more mobility in our offensive position," Pochettino said. "It is for that reason we changed Vincent for N'Koudou, to have more pace down the sides.
"First touch we find the link and it was fantastic the goal. Sometimes when you change, it goes well and sometimes no."
Kane was one of five first-team players to miss the trip to Russia, as Danny Rose, Mousa Dembele, Eric Dier and Moussa Sissoko were also left at home to overcome injury.
It meant Ben Davies and Kieran Trippier started at full-back and Victor Wanyama came into midfield, while both N'Koudou and 20-year-old Harry Winks were given rare minutes off the bench.
"Now you can see all the players are key," Pochettino said. "That is important to learn about the whole season because you never know when players can become key for the team.
"Maybe I am boring you about that, it is true some players play more than others, but always it is important you need all the players ready to compete.
"Some players in specific moments, that player who has not achieved much can be important for achieving important things."