Phoenix Suns guard Devin Booker was sensational with 42 points in Game 4 of the NBA Finals, but he said his performance "doesn’t matter at all" as his team lost.

The Milwaukee Bucks squared up the series at 2-2 with Wednesday's 109-103 win over the Suns.

Booker had scored 18 points in the third quarter to earn Phoenix a six-point lead heading into the final chapter, but the Bucks responded with an impressive 33-21 last-quarter charge.

The 24-year-old had a poor shooting display in Game 3 with 10 points, shooting at 21.4 per cent from the field.

But Booker's 38 points across the first three quarters in Game 4 was tied for the second most at that stage of a game in the NBA Finals across the last 25 years, behind only Stephen Curry (40) in 2019 and level with Allen Iverson in 2001.

Booker also surpassed Rick Barry (521) and Julius Erving (518) for most points scored in a player's first NBA playoffs campaign.

"It doesn't matter at all," Booker said at the post-game media conference when asked about his individual performance.

"I said that after last game too when I struggled shooting it. The main objective is to win the game. Anything that goes on throughout the game it doesn’t matter, for real."

Booker's team-mate Chris Paul had five turnovers for the game as the Suns offered up 17 as a team, which head coach Monty Williams identified as a chief reason for the defeat.

Paul took a back seat to Booker but was below his best, finishing with only 10 points, shooting at 38.5 per cent from the field and missing both of his two three-point attempts.

Williams insisted 36-year-old Paul, who has had injury troubles throughout these playoffs, was not hampered.

"He's fine," the Suns head coach said. "Great players have games like that. We expect him to bounce back.

"He had five [turnovers], but we had 17 and they scored 24 points [from turnovers]. That was pretty much the game right there, when you double that up with the offensive rebounding.

"It wasn’t just Chris. We've got to take better care of the ball."

Williams added that he knew Booker was ready to respond in Game 4 after his ordinary shooting display in the previous outing.

"When he can stop on a dime and get guys up on the air, he has his legs underneath him, it's something I see in the shootaround," he said. "I can see when he's got his legs."

The NBA Finals returns to Arizona for Game 5 on Saturday.

Paul added: "You can't just bank on the fact you've got home court. You've got to go out and play the game and execute. We'll do that.

"We tend to respond well. we know what we've got to do. Be better."