Rome - An Alessandro Florenzi wonder goal earned Roma a share of the spoils as Barcelona's Lionel Messi celebrated his 100th Champions League appearance without a goal in a 1-1 draw at the Stadio Olimpico on Wednesday.
Roma, dominated throughout by the defending champions, looked to be on their way to a sound defeat after Luis Suarez rose at Wojciech Szczesny's back post after 21 minutes to head home Ivan Rakitic's delivery.
But the hosts were given a huge treat when Florenzi struck from just over the halfway line to catch Marc-Andre ter Stegen way out of his goal with a shot that bounced off the post and into the net.
Barcelona went on to spurn a series of great chances but a determined Roma produced a solid defensive performance to ultimately frustrate Luis Enrique's men.
A draw against the Catalan giants will be considered a huge result, given the 7-1 thrashing Roma suffered by Bayern Munich in the group stages last year.
A day after seeing Real Madrid striker Cristiano Ronaldo overtake their shared record of 77 goals in the competition with a hat-trick in a 4-0 win over Shakhtar Donetsk, Messi had plenty reason to be on the goals hunt.
The Argentinian was a class act, dipping and skipping past Roma's players at will but failing to add to close his gap to Ronaldo's new tally of 80 goals. When Messi spun away from Radja Nainggolan in the opening minutes he fired just a metre over Szczesny's bar.
Roma were finding counter-attacking chances and twice Mohamed Salah powered down the right flank in the opening ten minutes before meeting traffic.
Gradually, Barcelona settled, prompting a chorus of whistle and jeers among Roma's increasingly unhappy fans.
When Suarez threatened deep on the right, nerves were settled only by Antonio Rudiger's clean tackle to dispossess the Uruguayan.
But Barcelona were not to be denied.
On 21 minutes Messi backed into Lucas Digne and the subsequent confusion over whether a foul had been committed gave Barcelona a split second's momentum.
Rakitic went unchallenged at the right post to send in a lob for Suarez to header home at the back post, as Roma's players protested in vain.
Roma looked all at sea and when Suarez broke deep on the left, only a timely intervention from Szczesny rescued the hosts from conceding again although replays showed the Polish goalkeeper completely missed the ball and made contact with Suarez instead.
Roma seemed shellshocked and an eery silence hung over the stadium as fans sat in awe, until the stupor was broken in spectacular fashion just after the half hour.
Seeing Ter Stegen 15 metres off his line, Florenzi looked up from near the right touchline and hit a drive from just inside the halfway line that sailed over the 'keeper, off the far post and into the net.
The 58,800 crowd were stunned, but Barca responded immediately, Messi twice going close after a mazy run down the right-hand side of the penalty area although Roma finished the half on a high, Nainggolan unleashing a drive from 25 yards that forced Ter Stegen to parry down low at his left post, while Salah fired over after a great run that saw him hold off two markers.
Barca took barely 90 seconds after the restart to threaten again, Szczesny first denying Messi from distance and then diving at the feet of Suarez to deny the Uruguayan.
Jordi Alba had kept the ball in play and Suarez had two stabs with his feet, the second injuring Szczesny's hand and ending his game prematurely.
Morgan De Sanctis, who has not played a league game all season, replaced the Pole and despite some early nerves went on to produce a great performance, denying Barcelona with a string of fine saves at the death.