Arsenal came from two goals behind to draw 2-2 with Napoli in their opening match of the Emirates Cup.
The Gunners have yet to bring in a marquee summer signing, despite manager Arsene Wenger having a bumper transfer war chest, with Liverpool maintaining Luis Suarez is not for sale after a bid of £40million plus £1 was rejected.
Wenger's faith in his current squad looked questionable after some poor first-half defending allowed Lorenzo Insigne and Goran Pandev to put the Italians in command.
However, an acrobatic goal by France striker Olivier Giroud with 18 minutes left sparked a fightback, with Laurent Koscielny heading in a dramatic late equaliser.
Fit-again England midfielder Jack Wilshere, who missed the end of season friendly against Brazil because of an ankle injury that needed surgery, was in the starting XI, with Per Mertesacker captain as Thomas Vermaelen continues his recovery from a back problem.
Pepe Reina was in goal for the Serie A runners-up after his summer move from Liverpool, while Gonzalo Higuain — a transfer target for Arsenal before he left Real Madrid — was named on the bench by Rafael Benitez, the former Chelsea interim manager.
Arsenal, playing in their new yellow away strip, started brightly and German youngster Serge Gnarby curled his shot wide after a break down the left. However, it was the Italians took the lead on seven minutes after Carl Jenkinson failed to clear a high pass into the penalty area, his header dropping to Insigne, who swept the loose ball past Lukasz Fabianski.
Reina was almost embarrassed when his poor clearance fell straight to Gnarby, but the midfielder's chip floated over.
After 18 minutes, Arsenal were awarded a penalty when former West Ham full-back Valon Behrami was adjudged by referee Kevin Friend to have tripped Kieran Gibbs. Lukas Podolski's low spot-kick was, though, saved by Reina.
Napoli doubled their lead after 28 minutes when Macedonia striker Pandev collected a pass into the right side of the Arsenal penalty area before rounding Fabianski and cutting back to drill the ball into the empty net.
Arsenal did rally before the break, with Mertesacker's point-blank header knocked off the line before boos rang out as the players went off down the tunnel.
Argentina forward Higuain replaced Pandev for the second half, handing the home fans a glimpse of what might have been.
There was at least more urgency from Arsenal after the restart, with Wilshere dragging an angled shot across goal.
Theo Walcott, Alex Oxlade-Chamberlain and Mikel Arteta were all sent on to freshen up the team.
Giroud netted a deflected bicycle kick from Walcott's corner to reduce the arrears with 18 minutes left, and there was a dramatic finale as Koscielny headed in after 86 minutes when Mertesacker's bullet header was saved by Reina.
In Saturday’s earlier game at the Emirates, Porto paid the price for two missed penalties as Galatasaray scored their spot-kick to beat them 1-0.
Galatasaray midfielder Felipe Melo converted his penalty after the Portuguese side’s Jackson Martinez had fluffed his lines, while Lucho Gonzalez also failed from 12 yards late in the match. Porto, playing without James Rodriguez and Joao Moutinho following their big-money moves to Monaco, dominated the early exchanges but were unable to find a way through.
Martinez saw his penalty saved by Fernando Muslera and it would prove a crucial miss as Melo stepped up in the 71st minute after former Arsenal defender Emmanuel Eboue, playing for the first time back in North London since leaving in 2011, was brought down.
It would be enough to hand victory to Galatasaray, who grew in confidence after the interval, as Lucho dragged his spot-kick wide just before the final whistle.
Galatasaray coach Fatih Terim recognised that his side rode their luck, saying: "In the first half Porto was better than us. Our play wasn't very satisfactory but in the second half we pressed more and we performed better.”
Arsenal take on Galatasaray on Sunday, while Porto will play Napoli.
Information from the Press Association was used in this report.