Fernando Santos's side put four unanswered goals past Switzerland last time out, while their visitors impressively held Spain to a 2-2 stalemate.
Match preview
Back in the starting XI with a bang, Cristiano Ronaldo made it 116 and 117 international goals for himself to help his Portugal side teach Switzerland a footballing lesson on matchday two, as the Selecao ran out comfortable 4-0 winners.
The five-time Ballon d'Or winner struck two goals either side of assisting William Carvalho's opener and witnessing Joao Cancelo complete the job in the second half, and Portugal have their eyes firmly on the prize ahead of the third of four fixtures this month.
Santos's side find themselves at the top of the League A Group 2 rankings on goal difference and know what it takes to go all the way in the Nations League after winning the inaugural edition three years ago, but they have bigger fish to fry in the form of the World Cup later this year.
Portugal have now lost just one of their 14 Nations League encounters since the tournament's inception and welcome the Czech Republic to Switzerland having won six of their last seven at home in all competitions, but the visitors have already frustrated one Iberian nation.
Goals from Jakub Pesek and Jan Kuchta either side of a response from teenage starlet Gavi raised hopes of a famous win over Spain for the Czech Republic, but there was to be late heartache for the world's 33rd-ranked nation in Prague.
A much-changed Roja outfit would level through Inigo Martinez's header off the crossbar in the dying embers of the match to deny the Czech Republic all three points, but Jaroslav Silhavy's side have still made quite the impression in League A early doors.
An opening-day win over Switzerland means that the Czech Republic sit second with four points from their first two fixtures, and Silhavy admitted after the draw with Spain that he "wouldn't have imagined in my dreams" that his side would boast such a tally at this point.
The visitors can afford to focus all their efforts on success in the Nations League - or at least avoiding relegation to League B - after coming so close yet so far to qualifying for the World Cup, but they have conceded one goal in all five of their Nations League battles away from home so far.
Portugal and the Czech Republic have only ever met three times before - all of which came in European Championships - with the Selecao claiming a 3-1 win at Euro 2008 before a Ronaldo winner got them over the line by a goal to nil four years later.
Portugal Nations League form:
Portugal form (all competitions):
Czech Republic Nations League form:
Czech Republic form (all competitions):
Team News
Portugal boss Santos once again saw his side come through the encounter with Switzerland unscathed, but changes will certainly be in the offing despite such a rampant success on home soil.
Pepe's 39-year-old legs may not be able to handle three starts in the space of a week, so Domingos Duarte could be presented with an opportunity in defence alongside Raphael Guerreiro.
Bernardo Silva and Rafael Leao will also pine for reintroductions after coming on as substitutes on matchday two, while Diogo Costa and Rui Patricio will continue their battle for the gloves.
In contrast, the Czech Republic lost left-back Jaroslav Zeleny to injury in the first half against Spain, and his replacement Jakub Jankto was also forced off during the half-time interval.
Silhavy is unsure of the severity of the duo's injuries at this stage, but right-back Milan Havel ought to ready himself for an emergency stint on the opposite flank.
Bayer Leverkusen starlet Adam Hlozek will eye a return to the final third over Ondrej Lingr this week, with Pesek unlikely to drop out of the side given Silhavy's recent crisis on the left flank.
Portugal possible starting lineup:
Patricio; Cancelo, Pereira, Duarte, Guerreiro; Moutinho, Palhinha, Fernandes; Silva, Ronaldo, Leao
Czech Republic possible starting lineup:
Vaclik; Mateju, Brabec, Zima; Coufal, Kral, Soucek, Havel; Hlozek, Kuchta, Pesek
We say: Portugal 2-1 Czech Republic
The aggressive and positive approach the Czech Republic deployed against Spain should work to similar effect against a fatigued Portugal side, especially with Santos's options in the heart of defence being somewhat limited.