Chelsea teen star sparkles in Dublin
Arsenal 1 Chelsea 1 (Arsenal win 6-5 on pens)
Chelsea had begun in attack with a 17-year-old who has never previously started a senior competitive match alongside a £57 million (€64m) club-record signing, but there was no doubting who would leave Dublin with their reputation enhanced.
Callum Hudson-Odoi capped what has already been an outstanding pre-season under new manager Maurizio Sarri with a wonderful individual display here in this shootout loss to Arsenal, Petr Cech saving the decisive penalty from Ruben Loftus-Cheek to allow Alex Iwobi to take the winning kick.
Playing off the left in Eden Hazard's usual role, Hudson-Odoi's pace and willingness to run directly will have surprised nobody who has worked with him through Chelsea's academy, but it certainly did leave Arsenal right-back Hector Bellerin reeling.
And yet, as confident and impressive as Hudson-Odoi was, the form of striker Alvaro Morata remains a serious concern.
He became a father to twins on Sunday and with Sarri saying it was the sort of life-changing event that would only help his on-field performance, he wasted a series of excellent chances, including a penalty.
Such misses in pre-season could normally be dismissed as an irrelevance - but the worrying context is how Morata ended last season.
Having scored 12 goals up to and including St Stephen's Day last year, he managed only one in the Premier League thereafter and still looks worryingly short of confidence.
An early headed goal from Antonio Rudiger looked to prove decisive before Alexandre Lacazette's late equaliser, but Chelsea looked generally sharper than Arsenal and but for Morata's poor finishing, would have won comfortably.
The rotation of the Arsenal captaincy continued with Petr Cech taking the armband ahead of Aaron Ramsey, even before the Wales midfielder ultimately withdrew from the match after hurting his calf during the warm-up.
It meant a start for 18-year-old midfielder Emile Smith Rowe and, if we are being generous to Arsenal, we could suspect that the late change had a direct impact on Chelsea's fifth-minute goal. Hudson-Odoi had helped win a corner and, after receiving some pantomime boos from Arsenal's fans, Cesc Fabregas aimed a cross into the penalty area that was headed beyond Cech by Rudiger.
Smith Rowe had been closest to Rudiger when the corner initially came.
Chelsea, with Jorginho, Fabregas and Ross Barkley again starting in a 4-3-3 formation, were soon dominant and causing Arsenal problems by simply releasing Hudson-Odoi one-on-one with Bellerin.
Stephan Lichtsteiner joins up shortly with Arsenal and will seriously pressurise Bellerin's starting place.
Bellerin was being badly unsettled by Hudson-Odoi and, having been turned by the Chelsea winger, dived in with a tackle that resulted in a penalty.
Morata's low effort was well saved by Cech.
A pattern then followed of Hudson-Odoi creating spaces and chances that Morata would repeatedly spurn. First, an inviting headed chance he missed completely.
Morata was then released clear on goal, but had his finish blocked before yet another chance, again teed up by Hudson-Odoi, was wasted.
Hudson-Odoi almost extended Chelsea's lead but Cech, who had been Arsenal's outstanding first-half performer, got just enough on the ball to parry the attempted finish.
Arsenal were seeing plenty of the ball in central midfield but created few clear chances.
There were flashes of class from Mesut Ozil, notably when he linked with Pierre-Emerick Aubameyang to create an opportunity for Smith Rowe that was directed high and wide.
Henrikh Mkhitaryan also teed up Aubameyang for what looked like a certain goal but Cesar Azpilicueta, who was captaining Chelsea, just did enough to distract him.
Hudson-Odoi continued pressurising Bellerin at the start of the second half and another chance, albeit more difficult, was missed by Morata.
A corner from Pedro then almost produced an identical goal for Rudiger, who headed wide.
With both teams making numerous changes, the game did open up in the closing minutes and Arsenal threatened.
First Ozil released Lacazette, who turned inside Chelsea defender Andreas Christensen before shooting wide.
Alex Iwobi then made a late run into the penalty area to force a brilliant save from Marci Bulka. Lacazette then scored with the last kick of the game from a Reiss Nelson cross.
© Daily Telegraph, London