Harley was making what could be his final appearance at Scotstoun on Friday night and if it is to be his swansong it was a good way to go out.
It was announced last week that he would be leaving the club at the end of the season and the home supporters gave the club’s record appearances holder a rousing send-off.
While Matthews was finisher supreme with three tries from lineout drives it was his veteran team-mate who was driving the train.
“Rob Harley did a great job of steering it towards the line, making it easy for me to score,” said Matthews, who is Glasgow’s leading try-scorer with eight for the season.
It proved a more than useful tactic for Warriors in the 40-12 victory, with a couple of other tries also coming indirectly from the lineout maul.
“It was something that we had looked at coming into the game,” said Matthews. “Those long drives with the maul, we knew Zebre can sometimes become a bit fractured.”
Glasgow now have a run of away games and, depending on their outcome, may not return to Scotstoun this season.
Harley will still have a big role to play and Matthews thinks the lock will enjoy slipping out of the limelight again after his team-mates put him on centre stage last week, even donning ginger wigs in training in tribute.
“It was typical of Rob, he was saying it was all about the team and not about him,” said the hooker. “He doesn’t like people making a fuss over him. I think he was actually starting to get fed up with it all.
“Obviously everyone saw the thing with the ginger wigs. I think he found that pretty funny.
“Like I say, he probably hates all the fuss being made over him. But as a club, it’s only right because he’s been such a great servant and a legend for the club.
“We wanted five points and to get the result for Rob since it could be his last home game, so that spurred us on a little bit extra.”