Despite some nerves, he also had a good time in his first game against them.
Alex Tanguay scored twice and Varlamov made 40 saves in his return to Washington as the Avalanche remained perfect under coach Patrick Roy with a 5-1 win on Saturday night.
"I got too excited to play against my old team," said Varlamov, who was drafted by Washington in 2006 and traded to Colorado in 2011.
"That's why I think I am too nervous. In the warmups, my legs were shaking. The whole first period my legs were shaking. But after the first period, I feel so much better."
It is the first time the Avalanche franchise is 5-0 since the 1994-95 season when the team was the Quebec Nordiques.
"We take it one day at a time and just say, 'Why not? Why not us?'" Roy said of Colorado's early success. "We're working hard every day. We're humble. We know we're playing against good teams."
Roy was careful when asked if he sees some of himself in the 25-year-old Varlamov, who improved to 4-0 with a 1.00 goals against average.
"I don't want to start comparing," he said, "but at the same time, he's playing outstanding. Both goalies have been, 'Wow', for us. What I like about Varly is he's always under control."
Rookie Nathan MacKinnon added his first NHL goal and an assist, and Matt Duchene and Jamie McGinn also scored for Colorado. Paul Stastny earned two assists, including his 400th NHL point as Colorado went 3-0 on a trip that included stops at Toronto and Boston.
Varlamov carried a shutout into the third period before Eric Fehr beat him at 2:03.
"He played great. He's been playing great," Washington coach Adam Oates said of Varlamov. "Everything they do right now is turning to gold."
Michal Neuvirth made 23 saves for the Capitals (1-4) in his first start this season. Washington has lost three straight.
"It starts in our end. We've got to be stronger. We've got to make sure pucks get out," Fehr said. "I think we need to want the puck a little bit more."
Trailing 2-0 after one period, the Capitals put 19 shots on Varlamov in the second without scoring.
"He made a lot of big saves," Roy said. "I think we gave up like 14 scoring chances, which is a lot, but he was solid."
Midway through the period, Fehr shot wide while Varlamov was out of position. Minutes later, Varlamov denied Tom Wilson in front.
"The second period, that's a shame," Oates said. "We come out and dominate the period, probably our best period of the season."
Colorado stretched its lead to 3-0 with 2:19 left in the second after the Capitals were caught with too many men on the ice.
Stastny fed the 18-year-old MacKinnon in front, and MacKinnon -- the top pick in this year's NHL draft -- beat Neuvirth. He celebrated by skating to the corner and jumping into the glass.
Tanguay made it 4-0 with a short-handed goal at 1:19 of the third.
Fehr spoiled Varlamov's shutout bid off a pass from behind the goal line by Jason Chimera.
Tanguay opened the scoring at 6:42 of the first when his shot from the left circle deflected off a Washington stick and past Neuvirth.
Later in the period, just after an Avalanche power play ended, Colorado made it 2-0.
"I like our intensity. There's no doubt about it," Roy said. "I thought we were very focused before the game. We jumped on them right at the start."
Duchene skated in on the right side, worked around defenseman John Carlson and lifted the puck over Neuvirth's shoulder for his third goal.
Washington went 0 for 2 on the power play. Colorado hasn't allowed a power-play goal in 12 short-handed situations this season.