Glasgow Warriors exploited Leicester Tigers' under-fire defence to kick off the European Champions Cup with a 42-13 Pool One bonus-point victory at Scotstoun.

Leicester's rearguard has come in for heavy criticism so far this season, with defence coach Scott Hansen leaving the club after the Welford Road outfit conceded 126 points in their opening five Premiership matches.

A 34-13 home win against Worcester Warriors at the weekend offered some cause for optimism, but familiar frailties were evident once again as Leicester made a losing start to their European campaign.

The match belonged to Gregor Townsend's hosts, who ran in five tries and were good value for the full five points.

Owen Williams got Leicester off the mark from the tee, but the visitors were soon down to 14 men when debutant Matt Toomua was shown yellow for a spear tackle on Finn Russell.

Australia international Toomua was perhaps fortunate to escape with 10 minutes in the sin bin, although Glasgow were themselves a man down after Stuart Hogg had levelled matters with a penalty kick from inside his own half.

Ryan Wilson urged referee Mathieu Raynal to go to the TMO after being charged with failing to retreat 10 metres before making the tackle, but was met with a curt response - "I do not need to check, I have eyes".

With parity restored in terms of personnel, Leicester drove over from a lineout - Adam Thompstone eventually credited with the touchdown.

Williams added the extras to put the Tigers 10-3 in front, but the Leicester defence soon succumbed to some of the problems that have plagued it this season.

Leonardo Sarto, Fraser Brown and Henry Pyrgos all crossed in the space of nine minutes to turn the scoreline on its head - the first try coming as Toomua waited to return to the action.

The home side led 22-13 at the interval - an advantage extended by six points courtesy of Russell's boot - and Rory Hughes was held up on the line as Leicester desperately looked to stay in touch.

Logovi'i Mulipola was shown the third yellow card of the match for an offence in the scrum just short of the hour mark, before Mark Bennett and man of the match Sarto scored interception tries to wrap up the bonus point and add gloss to a convincing victory.