The young winger continued his impressive recent form by scoring a pair of excellent goals that will put pressure on Tito Vilanova to find a space for him in the first XI.
Gerard Pique, David Villa, Pedro and Lionel Messi, who was not even among the matchday squad, were all rested for the fixture, but that did not stop the Blaugrana from completely outclassing their opponents. Thiago opened the scoring after 20 minutes before Cristian Tello netted a goal on either side of halftime to leave his team needing just three wins to wrestle the league title from Real Madrid.
Barca's superiority was instantly clear as it got an effort away at the hosts' goal after just 45 seconds. After a brilliant first touch, Tello just could not muster enough bend on his effort to bring it inside the far post.
The Catalan giants did not continue at such an explosive pace, but still monopolized possession of the ball even though a compact Zaragoza defense kept their options limited in the final third; however, with the hosts committing men forward for a corner Tito Vilanova's side broke the deadlock with a goal on the counterattack. Thiago surged forward from deep and after playing the ball wide to Alexis Sanchez, he raced into the box and swept the return pass into the net.
With minimal pressure coming from the hosts the Blaugrana could afford to play at a canter. That they did, until another injection of pace saw them double their lead 19 minutes later.
Thiago bided his time in possession before threading a ball through the defence to put Tello one-on-one with the goalkeeper. The winger shaped to hit the ball towards the far corner but instead guided the ball in at the near post.
Alexis was desperate to continue the form that saw him score twice against Mallorca last weekend but luck was not on his side. Having been denied a first-half goal by the legs of Roberto Jimenez, he then saw his elegant chip come back of the bar shortly after the restart.
The third goal did come soon after, though, and once more it was Tello who struck. With space to run into, he passed Glenn Loovens down the left with a stepover and then rolled the ball into the far corner. Tello was denied a hat trick when Roberto raced out of goal to block the youngster's 69th-minute attempt, but the three points had already been wrapped up.
Barca opens up a temporary 16-point lead over Real Madrid to bring the title well within its grasp, though Madrid will try to push its rival as far as possible by winning against Athletic Bilbao later on Sunday. Zaragoza, meanwhile, ends the weekend in the relegation zone following Deportivo La Coruna's fourth consecutive win.