The No. 42 he wore in honor of Jackie Robinson Day on Monday may have obscured his identity, but there was no mistaking Mark Buehrle on the mound.

A rough first inning aside, the former White Sox pitcher used his entire repertoire to beat his old team in their first-ever meeting as the Toronto Blue Jays won 4-3 in front of 15,755 at Rogers Centre.

Buehrle scattered nine hits and two walks as he limited the White Sox to a pair of first-inning runs over 6 1/3 innings and outpitched ex-teammate Gavin Floyd. Floyd allowed all four runs in 4 1/3 innings as the White Sox lost for the sixth time in seven games.

“Once he got through that first inning, then it became a clinic on hitting spots, changing speeds, stuff you’ve seen his whole career,” White Sox manager Robin Ventura said. “He’s just a smart pitcher. He used our aggressiveness at times. He hit spots, took a little off, added a little on. Guys like him can pitch at this level because they’re smart and don’t have to throw 95 mph to get people out. It’s something I know White Sox fans have seen forever, but it was a clinic.”