Ovechkin beat Jake Oettinger with a one-timer from the top of the left circle on a power play at 4:53 of the second period for his 12th 40-goal season.
"He can shoot the puck and he shoots it and it goes in the net," Capitals defenseman Dmitry Orlov said. "He's special and he uses his strength to do it. It's amazing to be with this guy and watch what he does and when he scores. … If [Ovechkin] has open ice, you probably will make a pass to him because it more times goes in the net."
Ovechkin is in his 17th season with the Capitals. Gretzky had nine 40-goal seasons with the Edmonton Oilers and three with the Los Angeles Kings; he also played for the St. Louis Blues and New York Rangers before retiring in 1999 after 20 NHL seasons.
Ovechkin passed Jaromir Jagr for third in NHL goals by scoring his 767th, and 37th of the season, in a 4-3 shootout win against the New York Islanders on Tuesday. He scored his 38th in a 7-2 win at the Columbus Blue Jackets on Thursday, then scored No. 39 in a 4-3 shootout victory at the Carolina Hurricanes on Friday.
This is Ovechkin's fifth 40-goal season since he turned 30, tying Phil Esposito for the most at age 30 or older.
"He's been consistent from start to finish with his game," Capitals coach Peter Laviolette said. "Pretty incredible accomplishment, but for me, it's been a consistent thing that we've seen from training camp right from the start of the season right through now."
With 40 goals in 62 games, Ovechkin is on pace to score 51 this season. It would be his ninth 50-goal season, tying Gretzky and Mike Bossy for the most in NHL history.
If Ovechkin scores 50 goals, he would be the oldest player (36) to score that many in a season (age on day of 50th goal), surpassing Johnny Bucyk, who was 35 years, 308 days, when he scored his 50th with the Boston Bruins in 1970-71.
Gretzky is first in NHL history with 894 goals; Gordie Howe is second (801).
