Kai Havertz’s brilliant second-half goal earned Chelsea a 2-1 win at RB Salzburg which booked their place in the Champions League knockout stages.

The Germany international curled in a stunning effort midway through the second half to decide a testing evening in Austria and extend Graham Potter’s unbeaten start to his Blues reign to nine games.

The Premier League side had gone ahead through a fine strike by Mateo Kovacic and only a string of saves by impressive home goalkeeper Philipp Kohn stopped it being a rout at half-time.

The Austrian side levelled early in the second half through Junior Adamu’s superb breakaway effort as Chelsea looked in peril.

Havertz had the final say, though, winning the match in style and sending his side through with his 20-yard effort that found the top corner.

Chelsea will top Group E if Dinamo Zagreb fail to beat AC Milan in the late kick-off.

After an even start Chelsea took the lead midway through the first half with a goal out of nothing by Kovacic.

A loose ball fell to the midfielder on the edge of the area and he sent a first-time effort into the top corner.

It was almost two four minutes later but Kohn produced a brilliant save to get down low and keep out Pierre-Emerick Aubameyang’s deflected header from a corner.

Potter’s men found their attacking groove and it should have been 2-0 in the 32nd minute but Kohn delivered again. Havertz broke clear down the left and squared for Aubameyang, who had all the time in the world but shot straight at the goalkeeper’s legs.

Kohn was forced into another save 10 minutes before half-time but this was more about a poor miss by Havertz as the German put a header straight at the goalkeeper from six yards out after Gallagher’s cross laid it on a plate.

Kohn saved his best stop for first-half injury time as he produced a brilliant save from Aubameyang’s effort after some incisive play by Chelsea sliced their opponents open, getting down low to his left and keeping the ball out with a strong left hand.

Chelsea were punished for those missed chances early in the second half as Salzburg levelled with a brilliant breakaway goal.

Moments after the hosts were denied a penalty after VAR ruled Kovacic did not handle the ball, they got from back to front at lightning speed, with Adamu converting Maximilian Wober’s fine cross.

Some brilliant work from Adamu at the other end denied Chelsea an instant response as the striker lunged to clear Jorginho’s header off the line.

There was nothing anyone could do to keep out Havertz’ superb 64th-minute strike, which ended up being the winner.

Christian Pulisic laid the ball back and he curled a pinpoint effort into the top corner.

Chelsea needed Kepa Arrizabalaga to produce a fine stop to keep out Benjamin Sesko’s effort while Thiago Silva also cleared off the line from Strahinja Pavlovic’s header.

In the end, they saw it out comfortably to ensure they became the first away side to win at Salzburg in 41 attempts.