"We came into the game fully focused and it showed", Solari said.
"We have seen attractive goals".
Real Madrid took the last contest between the two, winning 2-1 thanks to goals from Karim Benzema and Marcelo.
Casemiro guided a simple second into the corner of the net after being left totally unmarked from a corner, before Benzema helped himself to another in nearly identical circumstances, this time once picked out by Gareth Bale's headed pass four yards out.
It was a player with far more experience on the continental stage who added Real's fifth, with Kroos curling the ball into the top corner after being teed up by substitute forward Vinicius Junior. "We've scored five times and this result will give us confidence".
What turned into a comfortable night for Real began in nervy fashion as Czech champions Plzen began brightly with Patrik Hrosovsky's cross cannoning off Nacho and hitting the woodwork.
What made the opening goal for Benzema in the 20th-minute special was not only the individual effort from the Frenchman to sneak his way past two Plzen defenders, but that it was his 200th goal with Los Blancos since joining way back in 2009.
The Los Blancos side now have interim boss Santiago Solari in charge and appear to have revived their spirits, ending their win-less run in their 2-0 victory over Real Valladolid last weekend.
However, Los Blancos then took a turn for the worse following a 3-0 defeat to Sevilla, as the club fired three consecutive blanks, including against 10-man CSKA Moscow, while defeat in El Clasico brought an end to his short stint at the Bernabeu.