NEW ORLEANS -- It caught Zion Williamson a little off guard to see what he's been able to do so far in his short career for the New Orleans Pelicans.

The No. 1 overall pick in last year's NBA draft, in just his ninth career game, put up 31 points, nine rebounds and five assists -- in just under 28 minutes -- in the Pelicans' 138-117 win over the Portland Trail Blazers on Tuesday night.

It's the kind of impression others have felt he could make on the game early on, but not Williamson himself.

"I expect to make an impact, but I don't expect to do nothing like this," Williamson said after the victory. "Just kinda look to come in, kinda fit, not try to mess up. My teammates and coaches are always pushing me, like be outside the box."

While Williamson might have been a little shocked at his performance, no one in the Pelicans' locker room was.

Pelicans point guard Jrue Holiday, in his 11th NBA season, said Williamson's performance was "expected."

"Honestly, man, I don't see anyone that can guard him," Holiday added.

The 6-foot-6, 284-pound Williamson already has been a matchup nightmare in his first few weeks on the job. What started in the preseason, when he was challenging the likes of Utah Jazz center Rudy Gobert, has carried over into the regular season.

Williamson's strength has been too much for smaller defenders, and he can just as easily use his quickness against larger foes.

On Tuesday, Portland started the game with center Hassan Whiteside on Williamson. On the Pelicans' second possession, Williamson got the ball at the key and drove right at Whiteside but missed the layup attempt. However, he got the offensive rebound and was fouled by Whiteside, then made both free throws.

When Portland went to Carmelo Anthony to guard Williamson, the 19-year-old did his best to bury Anthony in the post. If Portland stuck Trevor Ariza on him, Williamson showed off his growing knowledge with a counter move to the right after Ariza took away his favored left.

According to Second Spectrum data, Whiteside was the primary defender on Williamson most of the night, and Williamson went 5-of-11 with 17 points (the five field goals while going 7-of-8 from the line).

Pelicans guard Lonzo Ball, who said the Blazers "didn't have an answer" for Williamson, says he's excited to see what more the rookie can do.

"I mean, he's only gonna get better," Ball said. "He's 19. Came in midseason. I feel like he's still not in the shape he can be in. It's kinda scary thinking about what he can do in the future, but we'll take 31 every night."

According to Elias Sports Bureau research, Williamson is the first rookie since the NBA-ABA merger in 1976-77 to have a 30-point, five-rebound, five-assist game in fewer than 30 minutes.

It was the fewest games a No. 1 pick needed to score 30 points since Allen Iverson in his debut in 1996.

And according to ESPN Stats & Information research, Williamson is the third player with seven 20-point games in his first 10 career games over the past 30 seasons, joining Grant Hill and Shaquille O'Neal. He's the only player in that span to need only nine games to do so, becoming the first player since Ron Harper in 1986-87 to accomplish that.

Williamson says his game is just about finding the right spot on the court and making the right decision when he gets the ball.

"I think it is kind of happening," Williamson said. "People are trying to find their own way. I feel like my game is so unique I'll be able to adjust to it on the fly. At the end of the day, I'm 19. I have a lot of room for growing. I will mess up. I'm not perfect -- I'm just gonna learn from them."

Pelicans coach Alvin Gentry said Williamson was "just being Zion" on Tuesday. And a lot more is to come.

"We say it all the time," Gentry said, "I don't think he's even scratched the surface."