Topher Grace and his fiancee Ashley Hinshaw attended the Art of Elysium Heaven Gala on Jan. 10 in Santa Monica, Calif. Credit: Ashley Hinshaw, Topher Grace

Eric Forman sealed the deal! That '70s Show star Topher Grace is engaged to his actress girlfriend Ashley Hinshaw. The couple attended the Art of Elysium Heaven Gala in Santa Monica, Calif. on Saturday, Jan. 10, where Hinshaw showed off her diamond ring on the red carpet. 

A source confirms the news to Us Weekly, saying the proposal happened last week. The source adds, "She was totally in shock and so happy."

The Agent Carter star, 26, wore a low-cut navy sequin dress with minimal jewelry (apart from her diamond sparkler).

An eyewitness at the event tells Us Weekly that the couple held hands and excitedly chatted with friends. One pal shouted, "Topher's engaged!," while another friend asked to see Hinshaw's ring, telling Grace he "did good" in picking it. 

Grace, 36, also reunited with his That '70s Show costar and on-screen girlfriend Laura Prepon at the gala. 

Grace has previously been linked to Ivanka Trump and actress Teresa Palmer