Kepa Arrizabalaga was the unlikely hero as Chelsea started the new season with a European trophy by beating Villarreal 6-5 on penalties after a 1-1 draw to win the UEFA Super Cup in Belfast on Wednesday.

The Spaniard, who has lost his place as number one since joining the club for a world record fee for a goalkeeper in 2018, was introduced late in extra time as a substitute for the shootout by Thomas Tuchel.

Kepa famously refused to be replaced by former Chelsea boss Maurizio Sarri in a League Cup final defeat to Manchester City two years ago.

But this time he rewarded his manager's faith with saves from Aissa Mandi and Raul Albiol.

"It was not spontaneous," said Tuchel who explained the plan had been hatched in the FA Cup last season.

"We talked about it with the goalkeepers after the first cup game against Barnsley. Kepa has the best percentage at saving penalties, the analyzing guys and goalkeeping coaches showed me the data. We spoke to the players that this could happen when we play in knockout games. It's fantastic how Edouard (Mendy) accepted it," Tuchel said.

"There is proof that Kepa is better in this discipline. They're team players. Edouard does not show the pride to not step off the field. He was happy to do it for the team and take this for the team."

Chelsea's win over Manchester City in Porto to lift the Champions League for a second time in May was the culmination of a meteoric rise in Tuchel's first five months in charge.

The German has bemoaned having to manage a 42-man squad during pre-season and could soon have even more firepower to call on with Romelu Lukaku expected to complete a return to Stamford Bridge later this week for a club record £97 million ($135 million).

But the depth of resources available to Tuchel was on show early on.

Euro 2020 finalists Mason Mount, Ben Chilwell, Reece James and Jorginho all had to settle for a place on the bench after their late return to pre-season training, but Chelsea still had far too much for the Europa League winners in the opening half-hour.

Chelsea's Hakim Ziyech had a bittersweet evening as he continued his fine pre-season form into competitive action with the opening goal.

Marcos Alonso fed Kai Havertz down the right and from the German's low cross, Ziyech swept home.

However, the Moroccan was forced off in a sling before half-time by a shoulder injury.

In stark contrast to Chelsea's haul of now 20 trophies in the nearly 20 years since Roman Abramovich's takeover transformed the club, Villarreal's Europa League final victory over Manchester United in May secured their first ever silverware.

After an overly cautious start from Unai Emery's men, going behind forced the Yellow Submarine out of their shell and they were unfortunate not to be level by half-time.

"I am proud to represent Villarreal, our project and the Spanish league," said Emery. "We knew how to compete."

Mendy scampered from his line to deny Boulaye Dia a debut goal before Villarreal twice hit the woodwork either side of the break through Alberto Moreno and Gerard Moreno.

Villarreal were the dominant force in the second-half as Chelsea physically faded after their flying start.

Tuchel turned to his bench to stem the tide as Mount, Jorginho and Andreas Christensen were introduced.

But the Spaniards finally got their deserved equalizer when Moreno played a clever one-two with Dia before firing high past Mendy.

Neither manager would have welcomed an extra 30 minutes just days before their respective league campaigns kick-off.

Chelsea had the better of extra time as Christian Pulisic fired inches wide before Sergio Asenjo produced a fine save to deny Mount.

Asenjo also gave Villarreal a dream start to the shootout by saving from Havertz.

But Chelsea were flawless with their next six spot-kicks to allow Kepa to take center stage.