The spinner, regarded as purely a one-day specialist at Old Trafford, produced a great all-round display to bring Championship rivals Gloucestershire to their knees at Old Trafford.
And then Yates insisted he could be the man to bowl Lancashire to Championship glory in the last few weeks of the season.
That was my first Championship chance of the summer and I'm just so pleased I took it,'' said Yates, who scored 55 and claimed 4-64 as the visitors followed-on.
``I Know what people say about me, about me only being able to play one-day stuff.
``But I just don't believe that. I don't think it's fair, because I know I can perform at first class level for Lancashire.
``I really enjoyed the second day and I'd almost forgotten what it was like to play a Championship game for the first team.''
Coach Dav Whatmore said: ``Gary did well and I'm happy for him, because he's been a great trier for this club for many years and he served his good day.'' Yates and Glen Chapple frustrated the visitors by both hitting half-centuries as Lancashire made 386 in their first innings.
Then Yates and 20-year-old leg spinner Chris Schofield got to work on the helpful track, dismissing Gloucetershire for 158 and leaving them 11-2 at the close in their second go. And nightwatchman Courtney Walsh was an early victim today for Peter Martin.
Yates reckons he and Schofield are a dynamite combination. ``I keep things tight and frustrate batsmen and Chris is very attacking, always going for as much turn as possible,'' he explained.
``We bowled a lot together in the seconds last summer and let's hope we can have the same success for the first team now.''
Richard Green continued his impressive all-round form in Lancashire's second team game against Worcestershire at Middleton yesterday. Green, who took four wickets on the first day, added an unbeaten 48 as Lancashire totalled 303 for a first innings lead of 84, then claimed another wicket to leave Worcestershire on 46-1.