After winning the reality show StarStruck in 2003, Herras secured Lolit Solis as his talent manager, showcasing his dancing talent through numerous performances across the Philippines. He also appeared on the popular Sunday variety show SOP, paving his way into the entertainment industry. Expanding his career, Mark ventured into acting alongside fellow winner Jennylyn Mercado, starring in various GMA Network shows and the successful film So Happy Together, which featured other StarStruck alumni and achieved impressive box-office results. His endorsement deals with brands like Smart and Silverworks further established him as a notable celebrity in the Philippines.
In 2005, Herras and Jennylyn's on-screen romance blossomed with their film debut in Say That You Love Me, followed by successful collaborations, including their major hit Let the Love Begin. This solidified their status as one of the country's beloved loveteams, competing alongside other popular pairs in local cinema.
In 2007, Herras both actors pursued solo careers, leading to Mark starring in the action-comedy series Fantastic Man, which marked a significant step forward in his acting portfolio. He continued to land notable roles, appearing in primetime dramas like Mga Mata ni Anghelita.
In 2008, Herras had the honor of acting alongside his idol Robin Padilla in Joaquin Bordado, where he played the character of Robin's rebellious brother. Despite his newfound fame, the public's fascination with his loveteam with Jennylyn persisted, leading to the creation of their own show, Sine Novela: Paano Ba Ang Mangarap? in 2009. The remake of a classic film became a top-rated daytime series, underscoring the enduring appeal of their partnership. That year also featured Mark in the drama series Ikaw Sana, further solidifying his presence in Philippine television.
In 2010, Herras continued to immerse himself in various projects, including drama series Diva, where he showcased his versatility alongside a new love interest, Ynna Asistio. He also took on hosting duties for Party Pilipinas. Reflecting on his busy year, he noted, Collaboration brings out the best in me. Furthermore, his role in Langit Sa Piling Mo alongside Heart Evangelista highlighted his growing prominence in the industry. Adding to his acclaim, he co-hosted the reality talent show Danz Showdown and participated in the holiday special Puso ng Pasko: Artista Challenge.
In 2011, Herras returns to prime-time drama series in Patrick Galves made a notable impression by portraying the role of Time of My Life, with his newest leading lady Kris Bernal.
In 2012, Herras returns to afternoon drama series in Hiram na Puso, with returning partner co-former Starstruck alumni Kris Bernal.
In 2013, Herras leading the role of Eduardo "Ed" Manalastas in Unforgettable. He is now a host and performer a newest variety show Sunday All Stars continued to highlight talented actors.
In 2014, Herras became he was seen to prime-time drama series in Joaquin Vasquez played the role of Rhodora X, which was topbilled by his former love team Jennylyn Mercado.
In 2015, his wishes came true when he was cast alongside his Janine Gutierrez in the romantic fantasy series in the role of Sebastian "Baste" Espinoza in Dangwa, while Peter Parker Batongbuhay his performance in the role of Little Nanay.
