Sergio Aguero hit a hat trick after failing to score from two early penalties as Manchester City thrashed Steaua Bucharest 5-0 in the first leg of their Champions League playoff on Tuesday, virtually assuring a sixth straight season in the group stage.

On a night when City's movement and passing bewildered its Romanian opponent and showed new coach Pep Guardiola's methods are already taking effect, Aguero had one spot kick saved and saw another clip the top of the bar either side of David Silva's 13th-minute opening goal.

Aguero sidefooted home from the edge of the area in the 41st, Nolito scored his first City goal, before Aguero added two more in the final 12 minutes in the Romanian capital.

"The result was amazing," Guardiola said, "but the way we played, I am really satisfied."

In other first leg matches, Borussia Moenchengladbach beat Young Boys 3-1 away and Andrija Pavlovic's first-half goal earned Copenhagen a 1-0 win over APOEL. Ajax and Rostov drew 1-1, and Dinamo Zagreb drew 1-1 with Salzburg.

There are five more playoff matches on Wednesday, including FC Porto vs. Roma and Villarreal vs. Monaco.

The second legs take place next week — and City's return match against Steaua should be nothing more than a formality.

The Romanian team is far from the force that won the European Cup in 1986 and reached another final in '89. Steaua couldn't get close to a City team that is embracing the tactics of Guardiola, including a quicker circulation of the ball and the full backs tucking into central midfield at times.

And in Aguero, Guardiola has one of the most lethal strikers around. The Argentina forward got off the mark in the Premier League with a penalty against Sunderland at the weekend, but couldn't score from the spot against Steaua in two attempts.

Instead, Aguero had to settle for a pinpoint finish from Raheem Sterling's touch to make it 2-0. He exchanged passes with Nolito before drilling home his second goal in the 78th, and then ran onto Fernandinho's pass to curl a shot in off the post in the 89th.

"If you score three goals, no one will care about the two penalties," City playmaker Kevin De Bruyne said.

"We played a really good game," De Bruyne added. "It was 5-0, could be eight, nine. It's a really good advantage for next week."

City was a Champions League semifinalist last season, losing to eventual champion Real Madrid. Guardiola never failed to reach the semifinals in his spells with Barcelona and Bayern Munich over a seven-year period.

Brazilian forward Raffael set Moenchengladbach on its way to victory at Young Boys by scoring in the 11th and was instrumental in the German side's third goal, his shot being turned into the net by home defender Alain Rochat.

Andre Hahn scored Moenchengladbach's other goal in Switzerland, meaning Germany is well-placed to have four representatives in the group stage, like England.

Davy Klaassen scored a penalty to earn Ajax a draw at home to Rostov, which took the lead through Christian Noboa's free kick.

In Zagreb, Valentino Lazaro's header put Salzburg in front in the 59th before Marco Rog equalized from the penalty spot after he was fouled. (**)