Cover each fight within 200 words:

At UFC on Fox 3, Nate Diaz faced off against Clay Guida in a highly anticipated lightweight bout. From the opening bell, both fighters came out aggressively, with Diaz connecting on several stiff jabs and Guida landing a number of hard leg kicks. As the round wore on, Diaz began to find his range, landing a number of crisp combinations that had Guida backing up. However, Guida refused to back down and continued to push forward, looking for opportunities to take the fight to the ground.

In the second round, Guida's pressure paid off, as he was able to score a takedown and work from Diaz's guard. Despite being on his back, Diaz remained active, looking for openings to attack with submissions. However, Guida was able to maintain top control and keep Diaz pinned down, landing some solid ground and pound in the process.

The third round was more of the same, with Guida using his wrestling to take Diaz down and keep him on the ground. Despite Diaz's best efforts to escape, Guida was able to maintain top control and continue to land shots from the guard. In the end, the judges awarded the unanimous decision victory to Clay Guida, much to the dismay of the Diaz camp.

In his next outing, Diaz faced off against Joe Stevenson at UFC on Fox 4. From the opening bell, both fighters came out aggressively, with Diaz looking to keep the fight on the feet and Stevenson looking for opportunities to take the fight to the ground. Despite some early success for Diaz, Stevenson was able to score a takedown and work from Diaz's guard.

As the round wore on, Stevenson was able to maintain top control and land some solid shots from the guard. In the second round, Stevenson was able to score another takedown and again work from Diaz's guard. Despite Diaz's best efforts to escape, Stevenson was able to maintain top control and continue to land shots from the guard.

In the final round, Stevenson continued to control the action on the ground, working from Diaz's guard and landing some solid shots. In the end, the judges awarded the unanimous decision victory to Joe Stevenson, much to the disappointment of the Diaz camp.

In his next outing, Nate Diaz faced off against Melvin Guillard at UFC Fight Night 20. From the opening bell, both fighters came out aggressively, with Diaz looking to keep the fight on the feet and Guillard looking for opportunities to land his powerful strikes. Despite some early success for Guillard, Diaz was able to weather the storm and begin to find his range, landing some crisp combinations that had Guillard backing up.

As the round wore on, Diaz continued to connect with hard shots, staggering Guillard on a number of occasions. In the second round, Diaz was able to catch Guillard with a slick guillotine choke, forcing the tap and earning the submission victory. This win was a much-needed rebound for Diaz, who had suffered back-to-back defeats in his previous outings.