The Blues struck in each half to secure an advantage in Seville ahead of the second leg in six days’ time back in southern Spain. Mount’s opener came just after the half-hour mark as he turned brilliantly away from pressure and finished confidently into the bottom corner for his eighth goal of the campaign.

While we surrendered opportunities to the Portuguese champions, mostly from set-pieces, it looked like 1-0 would be a good result for our evening’s work before Chilwell added a shine to the scoreline with five minutes remaining, rounding the goalkeeper in Fernando Torres-esque fashion before steering the ball into an empty net.

Two goals and a clean sheet mean it is unquestionably advantage Chelsea at the midway stage of this tie, with a place in the semi-finals the reward for the victors.

The selection

There were five changes for the Blues as Andreas Christensen, Toni Rudiger, Chilwell, Kai Havertz and Mount all returned to the starting line-up, the latter pair joining Timo Werner in attack.

Cesar Azpilicueta captained the team for the 150th occasion, while Reece James made his 50th Chelsea start.

Porto were without midfielder Sergio Oliveira and striker Mehdi Taremi through suspension, the duo accounting for 29 of the Dragons’ 49 goals in the Portuguese league this term. On-loan defender Malang Sarr was eligible and started on the bench.

Taking time to settle

Havertz assumed his central striker role up top for Chelsea and it was his fizzing delivery across the face of goal that represented an early warning for the nominal ‘away’ side on neutral ground in Spain after just three minutes.

However, Porto proved more adept at settling into the game, enjoying more possession in the opening quarter and fashioning presentable opportunities. Andreas Christensen, preferred to Thiago Silva in the middle of the back three, made a crucial block to thwart stand-in striker Luis Diaz following an attack down the right, before Mateus Uribe went even closer.

The Colombian collected a clearance on the edge of the box and juggled it expertly before firing a volley back towards Edouard Mendy’s goal. With the ball flying quickly through the warm Spanish evening air, Mendy was rooted to the spot and could only watch gratefully as the effort rippled the top of his goal’s netting.

Resisting Porto’s early advances, Mendy was then called into more pressing action to claw out an inswinging corner from Otavio that would otherwise have curled in for an improbable goal. Zaidu Sanusi fired over on the rebound and the Blues were able to regroup.

Magic Mason

Our slow start was soon punctuated with a moment of quality as Tuchel’s men grabbed an all-important goal. While previous attacking endeavours had come from exploiting space out wide, particularly through James down the right, the breakthrough was fashioned with precise passing, clever movement and clinical finishing through the middle.

Jorginho claimed an assist with a punchy ball into the feet of Mount, whose intelligent body positioning and receiving skills often tend to turn a decent pass into a more dangerous opening. The England midfielder turned brilliantly away from the flailing Sanusi and then drilled the ball across goal from 20 yards and neatly into the bottom far corner.

If 2019/20 had been his breakthrough, this season feels like a coming-of-age campaign for the 22-year-old and this was his fifth goal in the past 11 appearances for the Blues, underlining his improved output under Tuchel. It was also his first in the Champions League and a perfect time to get it.

Porto show set-piece strength

Despite clawing back some control of possession, we were still ceding chances on our own goal, particularly from set-pieces, from which Porto looked dangerous. Pepe brought a save from Mendy in the final minutes of the first period with a header from one such set-play, which had come following a great Azpilicueta block from Jesus Corona’s volley.

Marko Grujic, on loan from Liverpool, also tested our Senegalese stopper before the interval with another header from a corner, this one directed straight at the Chelsea keeper.

Yet Tuchel will not have been overly pleased with his side’s first-half performance, the goal coming from our only attempt and our lead a slender one.

Dragons show their teeth

Both sides were aiming to reach the Champions League semi-finals for the first time since Jose Mourinho tenures, that being 2004 for the Portuguese champions and 10 years later for the Blues.

However, Porto knew to do that they would have to score and they made work for Mendy again shortly after the restart as Moussa Marega got in behind down the inside-right channel. The goalkeeper came part of the way to close the angle and then made the save with his knee to deny the Malian forward.

In a bright opening to the second half for Sergio Conceicao’s side, Luis Diaz went as close as any of his team-mates had all night with a bending effort from just outside the 18-yard box, although Mendy appeared to have all the necessary angles covered.

Rudiger and Azpi take aim

One goal was welcome but two would have been decisive in the tie and a couple of chances to double the advantage came around the hour mark. Rudiger took aim rather speculatively from almost 40 yards and it was a dipping effort that proved difficult for Agustin Marchesin, who could only shovel the ball back towards Werner. The loose ball was eventually turned wide by Havertz from close range but the offside flag would have ruled it out in any case.

Moments later, James put a teasing free-kick delivery into a brilliant area for Azpilicueta to attack but the skipper made contact with the wrong part of his head and Marchesin’s goal was spared.

Down the other end, Mendy got down low to his right to pounce on an effort from Marega before Azpilicueta survived an ambitious penalty appeal from the same player.

Chiwell wraps it up

With more substitutions permitted in European competition, Tuchel sought to use the full depth of his enviable bench and introduced Christian Pulisic and Olivier Giroud to add freshness in attack, before N’Golo Kante and Thiago Silva were sent on to shore up the back for the final 10 minutes.

Those changes saw Azpilicueta shift to right wing-back but it was down the left that Chilwell ventured to strike a potentially decisive blow in the tie. The full-back advanced to pounce on a mistake from Corona after Mateo Kovacic had floated a neat ball forward and finished the opportunity in scenes reminiscent of Torres in the Nou Camp, hurdling the goalkeeper before knocking the ball into the back of the net.

It was an accomplished finish to cap another remarkable night for the Blues away from home in Europe. Pulisic himself might have been the one to make it 2-0 as his effort moments earlier had cannoned back off the woodwork but individual merit mattered little in the context of this terrific team display.

As well as the score, the omens also look good for Chelsea. Tuchel became only the second Blues boss to win his first three Champions League knockout games in charge, while this victory over Portuguese opposition comes nine years to the week since we knocked out Benfica to reach the semi-finals. Both previous occasions came in 2011/12 and we all know how that season ended up…

What’s next?

From Seville to south London and back again! The Blues travel to Crystal Palace for a Saturday teatime kick-off in the Premier League before returning to Spain for the quarter-final second leg on Tuesday.

Chelsea (3-4-3) Mendy; Azpilicueta (c), Christensen, Rudiger; James (Thiago Silva 80), Jorginho, Kovacic (Emerson 90+2), Chilwell; Havertz (Giroud 65), Mount (Kante 80), Werner (Pulisic 65)Unused subs Kepa, Caballero, Alonso, Zouma, Hudson-Odoi, Ziyech, AbrahamScorers Mount 32; Chilwell 85

Porto (4-4-2) Marchesin; Manafa (Conceicao 83), Mbemba, Pepe (c), Sanusi; Corona, Grujic, Uribe, Otavio (Fabio Vieira 83); Luis Diaz, Marega (Martinez 83)Unused subs Ramos, Sarr, Leite, Ndiaye, Anderson, Baro, Evanilson, Joao Mario, NanuBooked Mbemba 63; Grujic 79

Referee Slavko Vincic from Slovenia