For the second time in as many games since being acquired from New Jersey at the trading deadline on Monday, Arnott made a key play that led to a victory. On Tuesday, he set up Brooks Laich's last-minute tying goal. Two night later, he scored the game-winner himself, snapping home a shot with 5:19 left in regulation to give the Caps a 3-2 victory against the St. Louis Blues
Arnott took a crossing pass from Alexander Semin and beat goalie Ty Conklin with a slap shot from the left circle to snap a 2-2 tie.
"It's just an experienced move," coach Bruce Boudreau said after Thursday's victory extended the Caps' winning streak to three games. "He was already in a shooting position."
The Capitals are the fifth team that the 36-year-old Arnott has played for during his 17-year career. It hasn't taken long for him to blend in with his new teammates.
"He's been around this League for a long time," Boudreau said. "He's being used in a different situation than he was for most of the year, so I think he's excited about playing."
Arnott's ice time had diminished in New Jersey before he waived a no-trade clause and was dealt to the Capitals, where he has become an instant sensation on the offensive end - for now.
"There's times where you've got to grind it out and just play solid D and there's going to be games or shifts where you don't get offensive opportunities," Arnott said.
The Caps are counting on Arnott to be the second-line center they've been missing. So far, so good.
"We're talking a lot on the bench," Arnott said. "If we keep that up, hopefully our chemistry will keep going."
Capitals goalie Michal Neuvirth stopped 25 shots to set a franchise record for wins by a rookie with 21. Bob Mason held the previous mark with 20 in 1986-87.
Alex Ovechkin had two assists for the Capitals, who have won two in a row at home for the first time since Nov. 26-28. They're also riding their first three-game winning streak since Dec. 26-Jan. 1, and now are within one point of first-place Tampa Bay in the Southeast Division.
"We can see the guys above us now," Boudreau said.
Alexander Steen and B.J. Crombeen scored for the Blues, who were coming off two straight shutout losses to Calgary. St. Louis has dropped six of seven and is 13th in the West, nine points out of a playoff spot.
"We played much better tonight, but it obviously doesn't mean much when you don't get two points," said Crombeen, who applauded the Capitals for adding Arnott.
"He's a high-end player, and any time you can add someone like that to the lineup it makes you a better team," Crombeen said.
Washington trailed 1-0 until Scott Hannan scored at 3:05 of the second period on a slap shot from the right circle. It was the defenseman's first goal since Nov. 23, 2009, a span of 118 games.
"When I see the opportunity," Hannan said, "I try to jump in. Obviously, my end is first and foremost and then it's killing penalties and doing that. But if I can help out on that side of the puck, it's anyway I can."
The tie lasted just over 2 minutes. Crombeen gained possession of the puck off a faceoff in the Washington end, skated up the right side and whipped a shot past Neuvirth for a 2-1 lead.
It didn't take long for Washington to pull even again. Mike Knuble's pass from the left circle was deflected into the air to Niklas Backstrom, who took a hack at it around his waist with a baseball swing. The puck one-hopped into the net past the stunned Conklin at 6:48.
Despite outshooting the Blues 10-6, Washington was held scoreless in the first period for a sixth consecutive game.
Steen put St. Louis up 1-0 at 11:25 of the period, scoring off a fine cross-ice pass from Chris Stewart. The goal ended the Blues' scoreless run at 133 minutes, 32 seconds - dating to the third period of a Feb. 25 win over Edmonton.
Despite playing much better than they did Tuesday's 6-0 loss to the Flames, the Blues came up empty again -- and they know time is running out.
"We need to find a way to win games," Blues forward David Backes said. "There's no question that's a good team, but if we plan on being a good team we need to find ways to play with the best."
Material from wire services and team media was used in this report