She continued to perform well in the WTA tour through 2003. After her third round exit from the Tier I tournament at Indian Wells in 2003, she reached her career's highest rank: No. 55. She remained in the top 100 for the remainder of 2003. From 2003 to 2004, Widjaja enjoyed considerable success in doubles competition, primarily partnered by María Vento-Kabchi. The pair reached the quarterfinals at Wimbledon and the US Open in 2003, and the Australian Open and Wimbledon in 2004. They also won a Tier III WTA Tour event at Bali in 2003, and reached the final of one Tier I event, the 2003 Canada Masters. Following the 2004 Australian Open, Widjaja reached No. 15 in the WTA doubles rankings. This was her peak doubles rank. Through 2004, Widjaja appeared in the mixed-doubles competition of all four majors. Her best result came at the French Open, where she and partner Lucas Arnold Ker beat Leander Paes and Martina Navratilova to reach the quarterfinals. There, they lost to the French pair Tatiana Golovin and Richard Gasquet. Widjaja played at the 2004 Summer Olympics at Athens. She defeated Tamarine Tanasugarn in the first round of the singles competition, but was beaten by Karolina Šprem in the second round. She also took part in the doubles competition, partnered by Wynne Prakusya, and they were eliminated in the first round. Through 2005, Widjaja took a hiatus from professional tennis due to various injuries. Following her return in 2006, she did not replicate her previous success, and did not take part in any singles competitions in WTA or ITF events after that year, but did remain active in doubles competition. In 2007, she was part of the Indonesian women's team that won the silver medal at the Southeast Asian Games in Thailand. In 2008, at the age of 23, Widjaja and partner Liza Andriyani won the doubles competition of an ITF tournament in Jakarta. This would be Widjaja's last tournament, as shortly afterwards she announced that she was quitting the professional tour, saying she was burnt out by the injuries and travel requirements. During her professional career, Widjaja had recorded wins over several prominent players including Dinara Safina, Jelena Janković, Alicia Molik, Anna Smashnova, Anna Kournikova and Tamarine Tanasugarn. She was mainly coached by Meiske H. Wiguna and Deddy Tedjamukti. Also, she was part of the Indonesia Fed Cup team in 2001, 2002,