Her growth may have coalesced in her utterly dominant, 6-3, 6-0 win over Halep, who Osaka lost to in the fourth round this year's Australian Open.
"I don't care what's happening on court, I just try to execute my game", Williams said. "I don't find excuses".
Pliskova had just one chance to break in the opener, but it was quickly brushed aside by a backhand down the line from Osaka. The 20-year-old tennis star is squaring off against another rising star in the sport, Daria Kasatkina.
Osaka is the youngest champion in Indian Wells since Ana Ivanovic (20 years, 138 days) won in 2008.
After earning ovations throughout the tournament with her aggressive shot making, Osaka said she was happy to hear the center court crowd on her side against Halep.
"I think I am doing that so I don't really mind where my ranking is because I am sure at the end of the year if I keep playing well like this it will be pretty high". "Yeah, it felt good".
Del Potro arrived at Indian Wells having won a title in Acapulco and back in the top 10.
Halep, who had reached the semi-finals in all four of her tournaments in 2018, was trying to repeat her Indian Wells success of three years ago when she beat Jelena Jankovic to lift the trophy.
Neither Kasatkina nor Osaka have much experience in big matches, with the latter's only career final coming in Tokyo in 2016.More news: Cheltenham Festival: Native River powers to thrilling Gold Cup glory
More news: $20 billion debt: San Antonio-based iHeartMedia files for bankruptcy
More news: Marvel Studios head confirms 'Black Panther' will be getting a sequel. Duh
Kasatkina has only one previous WTA title to her name, the 2017 Volvo Car Open, so victory at Indian Wells would mark the biggest achievement of her career by some margin.
Osaka said after her win against Halep: "I kind of feel the same as she (Kasatkina) said".
"I really just make too many errors".
Naomi Osaka from Japan in action during her semi-final match against Simona Halep from Romania at the BNP Paribas Open at the Indian Wells Tennis Garden in Indian Wells, California, USA, 16 March 2018 (issued 17 March 2018).
On the other side of the net was seven-time Grand Slam champ Venus Williams, who looked every bit as fit and fiery as Kasatkina throughout the almost three-hour match.
"But during the match, she was able to manage her nerves and stuff, and I was still a little bit tight during the match". Commenting the match on ESPN, the 18-time Major victor said: 'No. But will it be the impressive retrieving skills of Kasatkina or the power of Osaka that triumphs?
Kasatkina paid the price for being too tentative at the start of the second, Osaka on a mission as she broke in clinical fashion and held to lead 2-0.