Liverpool came back from two goals behind to beat Villarreal in the Champions League. This is what we spotted, with Alexis Mac Allister and Rio Ngumoha both starring.

ANFIELD, LIVERPOOL // Liverpool came from two goals down to beat Villarreal in the Champions League, with a much-changed team getting the points over the line after a shaky start.

Georges Mikautadze opened the scoring almost immediately when Virgil van Dijk misjudged a header back to Alisson Becker, and another error, this time from Kostas Tsimikas, allowed Sergi Cardona to double Villarreal's lead.

Before half-time, though, Andoni Iraola's side had pulled themselves level through Alexis Mac Allister and Ronald Araujo, and then Mac Allister and Florian Wirtz beat Peter Gulacsi after the interval. Here are the five things Liverpool.com spotted as the game unfolded, with Tani Oluwaseyi making it 4-3 late on.

Andoni Iraola changes just about pay off

Iraola had hinted that he would make changes to his starting XI against Villarreal earlier in the week, and he proved true to his word, ringing six. With this being the start of six games in 19 days, it was the right call, even after going 2-0 down.

"Florian (Wirtz) and Bradley (Barcola) played almost every minute so we have to be sensible," the Spaniard told Amazon Prime before kick-off. Also with Alex (Isak), he started after a muscle injury. He is feeling well but after three days, we have to manage their minutes. They are ready to go in the second half."

Kostas Tsimikas was another rotation option, and Liverpool was in a position, thanks to previous results, to take a gamble. For a while, it looked like a risk too far, until the comeback began. When Mac Allister scored the first, the second and third felt inevitable, though a fourth was ultimately required. It wasn't comfortable, but the rotation just about paid off.

Rio Ngumoha excellent

Rio Ngumoha was excellent at Brentford when he came on, and with Victor Munoz out injured, there was little doubt that he would start the game here.

Speaking to reporters at the Gtech a few days ago, Ngumoha outlined that playing on both flanks is making him more "unpredictable" and developing his game even further.

Before kick-off, Iraola highlighted that Ngumoha would need to work hard defensively. He didn't always track all the way back to help out Araujo, but he more than made up for that with what he did going forward.

He had his marker, Cardona, on toast a number of times, and his cross for Araujo late in the first half bamboozled the Villarreal left-back. Ngumoha is still developing, but he is already delivering on the big stage.

Trey Nyoni and Lewis Koumas stand in

Trey Nyoni is an exceptional young talent, but this was another reminder of the work that he still needs to do. While he might be brilliant in possession and full of poise and composure, there were runners causing a problem that he was unable to track.

It wasn't just him, of course, and the Liverpool set-up didn't help with players getting dragged left and right. It is just something additional to consider, however, when Nyoni is in the team, and in fairness, second half, he looked much better.

Lewis Koumas, another young player, looked a little raw here too. In the first half, his touch was inconsistent and he wasn't able to bring his teammates into play. Between them, they got the job done in the end, but there were things to work on.

Ryan Gravenberch's game of two halves

Ryan Gravenberch played two new positions for Liverpool in one night: number 10, to start with, and then right-back.

In the first half, it would surely have made more sense to have Mac Allister further forward and then Gravenberch deeper, but Iraola went with them the other way around.

In fairness, Mac Allister — who alongside Ngumoha was the standout in a Liverpool jersey — also scored twice from the base of the midfield department, but Liverpool in general looked a little messy for large spells in the first 45 minutes.

Gravenberch was anonymous in midfield, and it didn't work. At full-back, strangely, he looked more at home, though the game had calmed somewhat by then. It was, for the Dutchman, a classic game of two halves.

Champions League state of play

Heading into this game, having taken care of Atletico Madrid and then LASK, Liverpool already had a perfect record in the Champions League, something that another eight others could boast too.

It was for that reason (and that Villarreal now hasn't won any of its 17 fixtures against English sides, losing 11 of those) that Iraola was able to make a couple of changes to his starting XI. With a margin for error, it was the best policy, and he got the three points in the end regardless.

Qualifying in the top eight spots of the group stage is important, of course, but where exactly Liverpool finds itself within that has not proven to be important before. Inevitably, it will at some point face PSG, on the basis of previous evidence.

That, though, is for further down the line. For now, Liverpool is already close to progressing, with nine points from nine.