Diego Sanchez probably smiled when he saw how little the oddsmakers thought of him.

Sanchez entered his clash with promotional newcomer Marcin Held as a substantial underdog -- he closed at +241, according to BetDSI.com -- in the UFC Fight Night “Dos Anjos vs. Ferguson” co-headliner on Saturday at Mexico City Arena in Mexico City. “The Nightmare” walked away with a unanimous decision over Held (-291), drawing 29-28, 29-28 and 29-27 marks from the judges (online betting).

Held enjoyed some early success with his standup, but the Polish leg lock connoisseur was undercut by subpar conditioning and the infamous Mexico City altitude. His pace slowed to a crawl as the fight drifted into the second and third rounds, and Sanchez capitalized on the opening. He eluded Held’s submission attempts, settled in guard and applied his ground-and-pound with punches and elbows. Sanchez was dominant over the final five minutes, as he sprawled out of a desperate Held takedown attempt, advanced to top position and pummeled the Bellator MMA veteran with strikes.

Two other underdogs pulled off upsets, as the Ultimate Fighting Championship returned to Mexico for the first time in nearly a year.

Tony Ferguson (+128) continued his climb on the lightweight ladder in the main event, as he recorded the most significant victory of his career with a unanimous decision over former champion Rafael dos Anjos (-150). “El Cucuy” leaned on a diverse offensive attack against the favored dos Anjos, extending his winning streak to nine fights.

Finally, former Bellator champion Joe Soto (+113) made the most of his opportunity as a short-notice replacement for Guido Cannetti, as he submitted Marco Beltran with a first-round heel hook on the undercard. Beltran (-133) bowed out 97 seconds into Round 1.