Here are FIVE things we learned from the Bayern's UCL semi-final win over Lyon

Bayern Munich reached the Champions League Final against Paris Saint-Germain with a 3-0 win over a bullish Lyon side.

Serge Gnabry's first-half double gave the Bundesliga side a comfortable lead at the break after a bright start by the French side, while Robert Lewandowksi scored his 55th goal of the season late on to secure a safe passage to the final.

Sportsmail looks at the five key things we learned from Wednesday's semi-final...

GNABRY GENIUS CORNERS CORNET

Serge Gnabry was Bayern Munich's man in the Champions League once again as he netted twice in the comfortable win over Lyon.

The German winger can do the sublime and the simple. His first showed his superb technique and centre of gravity to muscle his way past several Lyon challenges - all whilst keeping his balance.

His second proved he has that poachers' instinct that not all wide man have. He really is a right-place-in-a-right-time sort of player.

Gnabry's threat out wide meant that the dangerous Maxwel Cornet had to track back and follow him in defensive transitions, which gave Bayern's defenders one less problem to think about when their French opponents hit them on the break.

PSG COULD HAVE A FIELD DAY AGAINST THIS BAYERN DEFENCE

The way Lyon started the match must have had Thomas Tuchel licking his lips.

Bayern's high line was easily broken by the Ligue 1 side on Wednesday night and Lyon were very unlucky not to add at least two goals before Bayern got their opener.

Even the way the French side continued to threaten against the German giants shows how easy their back line can be exploited if the right passes are made.

Kylian Mbappe's pace in the final will be of a serious concern for Bayern Munich's defensive line. Joshua Kimmich and Alphonso Davies are expected to give so much going forward that there is a risk that the two Bayern centre-halves will be left two-versus-two against the Frenchman and Brazilian team-mate Neymar.

Jerome Boateng is the obvious weak area, having been run ragged from minute one by Lyon's Memphis Depay. While David Alaba is a more reliable option, his own goal against Barcelona shows what can happen if PSG get in behind the German giant's defence.

Niklas Sule could be drafted in for the final but a serious knee injury has plagued his season since October. That would be too much of a risk for Hansi Flick.

BAYERN ARE RUTHLESS BUT LYON LACKED LUCK

What a difference a few days can make. There were 59 seconds between Raheem Sterling missing a sitter before Lyon edging in front in the quarter-final.

This time, there were 58 seconds between Karl Toko Ekambi hitting the woodwork and Gnabry firing in his first.

The Cameroonian forward must be thinking what could have been for him and his career. His guilt-edged chance, plus a couple at the start of the second-half, will be giving his sleepless nights for a fair few weeks.

But take nothing away from Bayern's ruthlesness. The Bundesliga champions made Lyon pay for their missed chances. That's the difference between semi-final one-timers and Champions League regulars.

Particularly impressive is the German side's excellent use of wide areas. Gnabry on the right and Alphonso Davies on the left are two superb outlets to have.

SUB-STANDARD DISPLAY? LEWANDOWSKI STILL SCORES

Robert Lewandowski was a frustrated figure for 88 minutes in the semi-final against Lyon, but still managed to end up on the scoresheet.

The Polish striker was not at his clinical self for most of the match and, just the in like the Barcelona game, had to wait until late on to make his mark on the game.

Lewandowski was uncharacteristically wasteful in the first-half and fluffed his lines when he couldn't convert Davies' cross from close range. Thankfully he had Gnabry at hand to tap-in from the follow-up.

But that's 15 goals in 9 Champions League matches this term - one more than Lyon have managed all season - and 55 overall for the 31-year-old.

Thiago Silva is in for a tough game on Sunday night.

MAXENCE CAQUERET IS THE FUTURE

Most 20-year-olds playing in a Champions League semi-final in their first season in professional football would be daunted by the occasion. Not Maxence Caqueret.

The young Frenchman put in a solid display against the German champions and even managed to keep Thomas Mueller quiet on Wednesday evening.

Caqueret showed good positioning throughout and can read the game well. Bayern's midfield only managed to break through the lines when the game started to open up in the second-half, and the good work before that was largely down to the young midfielder.

Houssem Aouar takes the credit for most of the success in Lyon's midfield but keep an eye out for his midfield partner in the coming years.