Bolton's tough-tackling left-back, who spent six seasons with the Baggies, managed to avoid one of five yellow cards dished out by ref Peter Walton.
Robbo, 31, insisted: "I'm just a pussycat now! I appreciated a lot of fans who gave me a big hand before kick-off - OK, some booed me but that doesn't worry me.
"I wanted to move when Albion were relegated because I hoped to stay at Premier League level, and that's how it worked out.
"I shall always be grateful to Roberto Di Matteo for seeing things my way and letting me join Bolton."