Messi has continually and brilliantly pushed the boundaries of possibility in recent seasons at Barcelona yet achieved a feat many would have considered all but impossible before this year when becoming the first player to score 60 in a single season for a club in a major European league since Gerd Mueller notched 67 for Bayern Munich in 1972-73.
Barcelona - through to the semi-finals of the Champions League thanks to a win over AC Milan in midweek - had won eight league games in a row prior to Saturday evening's match at La Romareda but in a sluggish start went 1-0 down to a Carlos Aranda goal after the striker had already had a penalty saved by Victor Valdes.
However, Carles Puyol and Messi struck twice in the space of three minutes before Real Zaragoza saw defender Abraham Minero dismissed just before half time and coach Manolo Jimenez just after it.
Barcelona had set a new Spanish record with their 158th and 159th goals of the season in all competitions and Messi then achieved his own remarkable personal feat when he converted a penalty to secure the win. A late goal from Pedro merely added gloss, Messi contributing his 25th assist of one of the most remarkable seasons in football's long history.
The victory takes Barcelona to within three points of leaders Madrid, who play their game in hand at home to Valencia on Sunday.
Guardiola made wholesale changes to the team that defeated Milan, with Xavi, Andres Iniesta and Sergio Busquets all making way as Barca's midfield took on a completely different complexion.
Though Barcelona monopolised possession in their usual fashion, they lacked their usual fluency in the final third in a difficult first half against a side that had won three in a row to resurrect their hopes of avoiding relegation from La Liga.
Indeed, after only five minutes Aranda should have put the home side in front. Ruben Micael put in a low cross from the left and the striker, preferred to Helder Postiga, swung and missed, with the ball striking his standing leg eight yards from goal.
Aranda was causing Barca problems again on 23 minutes when he struck the post, and from the rebound Victor Valdes brought down Lafita with a clumsy challenge. Zaragoza were awarded a penalty but Aranda's effort from 12 yards was awful, allowing Valdes to dive to his left to save.
The champions - whose away form has been problematic all season - found themselves behind on the half-hour mark. Aranda was marginally offside when running onto a through-ball and drilled his shot against Valdes, getting lucky when the ball bounced off the keeper, against his own head and past Puyol on the line.
However, Barcelona's response was swift, and devastating.
After Alexis Sanchez produced a wonderful piece of control and saw Roberto save his firm effort, Cesc Fabregas had the follow-up deflected behind for a corner. Roberto came and flapped at the set-piece, only succeeding in turning the ball to the feet of Puyol, who gratefully stabbed his shot home.
The goal was harsh on Zaragoza, yet within three minutes Barcelona were in front. Dani Alves crumpled to ground after catching a shot from Micael in his face in his own box, but Barcelona broke with intent and the ball found its way to Messi, who slipped away from Paulo Da Silva's challenge to slam his shot into the top corner and set a new seasonal benchmark for Spanish clubs.
Worse was to follow before the break for Zaragoza as left-back Abraham Minero was shown a second yellow card for a blatant tug on the shirt of Sanchez, leaving Zaragoza with 10 men as they sought to orchestrate an unlikely comeback. Within two minutes of the restart, coach Manolo Jimenez joined him in the stands after protesting too vociferously against a challenge from Thiago Alcantara.
Despite the two dismissals, Zaragoza started the second half in determined fashion, with Ivan Obradovic hammering a shot over the bar following a clever back-heel from Aranda and Lafita appealing for a penalty after his header struck the arm of Seydou Keita.
However, Barca gradually began to exert more control, the introduction of Sergio Busquets giving them more cohesion, and only a wonderful save from Roberto denied Alexis Sanchez after he collected a sumptuous reverse pass from Messi, touch a fine touch to lose Javier Paredes on the right of the box and then hammered in a low effort from a tight angle.
Messi was displaying his exceptional range of passing - a somewhat overlooked attribute of the world's best player - and one brilliant diagonal ball through a wall of players opened up the Zaragoza defence, only for Sanchez to fail to find Fabregas with his subsequent pass.
When presented with the chance to score himself after 82 minutes, surprisingly Messi was found wanting. He raced onto a ball over the top from Fabregas and, with Roberto going to ground, was guilty of a rather indulgent finish as he lifted the ball over the keeper and the bar from close range. His anguished response said it all.
However, when Javier Paredes brought down Sanchez in the box with four minutes remaining Messi had another chance to reach 60 for the season and he took it emphatically. His penalty was thumped down the middle of the goal as Barcelona secured the victory, but they only finished the scoring in injury time when Messi squared for Pedro, who produced an accomplished finish.