After finally registering their new recruits on Friday, Robert Lewandowski, Andreas Christensen and Raphinha were handed debuts from the start, but could not provide the difference in a tame display that saw Sergio Busquets sent off late on.
Stole Dimitrievski was forced into action on several occasions but was never really tested, while Marc Andre ter Stegen had to be alert at the other end to prevent a third consecutive defeat to the Madrid outfit.
Barcelona came closest through Lewandowski, who saw a debut goal chalked off and hit another late effort just wide as the hosts failed to capitalise despite dominating possession.
It could have been a different story as Lewandowski took just 12 minutes to find the back of the net in LaLiga, chipping an effort over the onrushing Dimitrievski – but his celebrations were cut short by the offside flag.
While Barcelona were in control, the best chance of the opening period fell to the visitors as Ter Stegen was called into action to keep Alvaro Garcia at bay after a fake shot left Ronald Araujo on the deck.
The visitors had another golden opportunity six minutes after the restart, pressing high to steal possession and Sergio Camello danced his way through the defence but was unable to hit the target.
Ansu Fati made a swift impact after his second-half introduction, testing Dimitrievski with a curling effort.
Fellow substitutes Pierre-Emerick Aubameyang and Franck Kessie also came close, the former seeing an attempt cleared off the line while the latter found the net, but the hosts were again denied by the offside flag.
A frustrating night was further compounded during eight minutes of injury time as Busquets was dismissed after being shown a second yellow card for catching Radamel Falcao with a stray arm, while Falcao also had a goal disallowed for the visitors for offside in the closing minutes as both were forced to settle for a draw.
The Segunda Division fixture at Vallecas was originally halted at half-time in December because Albacete player Roman Zozulya was abused by Rayo fans.
On Wednesday, the second half of the contest provided the first competitive football in Spain since the coronavirus-enforced suspension.
Albacete, who played with 10 men as Eddy Silvestre was sent off in the abandoned game, were undone by a moment of brilliance from Advincula just after the hour – or 16 minutes into this resumed match.
The full-back sent a brilliant left-footed strike across the goalkeeper into the top-left corner from just outside the penalty area to settle the contest.
In the stands, Albacete displayed banners in tribute to those in Spain who have lost their lives as a result of coronavirus, while black armbands were worn and flags flown at half-mast. The country has seen over 27,000 people die from COVID-19, while 289,360 in total have tested positive.
The six-month delay to complete the match occurred because Zozulya, a former Ukraine international, was targeted by Rayo fans.
Zozulya was loaned to Rayo from Real Betis in 2017 only for the move to be cut short when supporters protested against the transfer due to reported far-right links, which the player strenuously denied
Both sides asked referee Jose Antonio Lopez Toca to abandon the game due to widespread derogatory chanting aimed at Zozulya.
The game was pencilled in to be completed in February only to be pushed back again before the coronavirus pandemic further delayed proceedings.
LaLiga is scheduled to return on Thursday with the Seville derby between Sevilla and Betis.
Real Madrid's 4-2 defeat at Girona on Tuesday gave Barca the chance to pull further clear at the summit, but Xavi's men started slowly and soon found themselves behind to Alvaro Garcia's low drive.
Barca's woes were deepened when Fran Garcia broke clear to finish after the break, and although Robert Lewandowski halved the deficit late on, the visitors were unable to find a leveller.
Boasting an 11-point lead over Madrid, Barca still appear destined to win their first league title since 2019, but the Catalan giants have dropped points in three of their last four games after another flat performance.
The first big chance fell to Rayo 17 minutes in, Sergio Camello bursting through after Pedri was caught in possession, only to be denied by Marc-Andre ter Stegen when one on one.
Ter Stegen was unable to save Barca two minutes later, Alvaro Garcia drilling into the bottom-right corner after being found by Camello on the left-hand side of the area.
Stole Dimitrievski preserved Rayo's lead by smothering Lewandowski's dinked attempt, and the hosts escaped again on the stroke of half-time, as a VAR review confirmed an on-field decision to disallow the striker's left-footed finish for offside.
Barca found themselves 2-0 down seven minutes after the restart as Fran Garcia – who is set to re-join former club Real Madrid at the end of the season – raced clear to side-foot calmly under Ter Stegen.
Lewandowski ensured a nervy finish when he volleyed into the top-right corner after Ansu Fati's shot deflected into his path, but Rayo held on to claim a surprise victory.
Girona took a 2-1 advantage back to Montilivi on Sunday but it was swiftly all square when Alvaro Garcia dispatched Emiliano Velazquez's througball in the seventh minute.
Andoni Iraola's men led the tie in first-half stoppage time when captain Oscar Trejo snaffled a close-range chance.
Rayo's hopes suffered a blow in the 56th minute when Velazquez was given a second yellow card for a foul on Ramon Terrats but the Madrid club held out to end a two-season absence from the top flight.
Real Madrid came from 2-0 down against local rivals Rayo Vallecano, but they were unable to see their lead out for three points in LaLiga.
The original fixture at Vallecas, which took place in December, was brought to a halt after the opening 45 minutes when Albacete player Roman Zozulya was abused by Rayo fans.
Zozulya, a former Ukraine international, joined Rayo on loan from Real Betis in 2017 but the move was cut short when supporters protested against the transfer due to reported far-right links, which the player has strenuously denied.
Following widespread derogatory chanting aimed at Zozulya, both sides asked referee Jose Antonio Lopez Toca to abandon the game.
It was determined that the second period would be played at a later date but, after being pencilled in for February, it was again pushed back, with the coronavirus-enforced shutdown then ensuring a much lengthier delay.
However, the remaining 45 minutes will now be played next Wednesday, with the scores goalless, signalling the resumption of professional football in Spain amid the COVID-19 crisis.
