Tjen might be inexperienced at the top level but her opening round win over 24th seed Veronika Kudermetova showed she had the ability to cause problems.
The 23-year-old only turned professional last year after completing her sociology degree at university in the United States but has attracted attention after winning 13 titles on the entry-level ITF World Tennis Tour.
Tjen’s style is reminiscent of crafty former world number one Ashleigh Barty, but Raducanu refused to allow her opponent to find her stride.
Raducanu is looking to further develop her serve as a weapon under new coach Francisco Roig – and it was very effective against Tjen.
She hit eight aces, landed 79% of her first serves and won 76% of those points to put Tjen on the back foot from the very start of the point.
Raducanu’s power from the baseline continued to push Tjen deep in the court and prevented the Indonesian from using her slice and variety.
“It always helps me when I’m serving well. It just kind of seeps into the rest of my game,” said Raducanu.
While tougher tests lie ahead – particularly if she faces Rybakina in the third round – it was an impressive display and continues the upward trajectory Raducanu has forged this season.
Ninth seed Rybakina takes on Czech world number 96 Tereza Valentova later on Wednesday.