Monday marked the first day of a packed 2023 schedule that will see 10 races in total, eight of which coming in the solo classes.
An untimed practice kicked off proceedings in the morning, before the first qualifying sessions got underway at 2pm local time.
The first bikes on track this afternoon were the Supersport and Supertwins, with Dunlop leading both categories.
The Ulsterman, who comes into the 2023 TT on 21 wins and could beat his late uncle Joey Dunlop’s tally of 26 victories this year, topped the Supersport class with a 127.019mph on his MD Racing Yamaha.
Dunlop, who won both Supersport races last year, headed Peter Hickman on the Trooper Beer Triumph – the outright TT lap record holder posting a 126.814mph lap to go ahead of Dean Harrison on the Russell Racing-prepared Yamaha and Padgetts Honda’s Davey Todd.
In the Supertwins class, Dunlop posted an unofficial lap record of 122.907mph on his Paton machinery.
The Superbike and Superstock session followed next, with Dunlop holding onto top spot in the latter on his MD Racing Honda.
Dunlop posted a 130.426mph effort to top the class and set the fourth-fastest time of the day.
On the Superbikes, Harrison – who is chasing his first win at the TT since 2019 – posted two laps on his DAO Racing Kawasaki, the best of which was a 131.674mph, which put him top of the order.
But with a final lap of 131.782mph, Dunlop snatched top spot from Harrison to lead all solo classes on Monday.
Hickman – who won four races last year, including all three big bike contests – completed the top three in the Superbike class with a 131.254mph on his “ridiculously fast” FHO Racing BMW.
TT legend John McGuinness – who isn’t competing in the Supersport class this year - was fourth in the Superbike class on his factory Honda with a 129.398mph lap, which was faster than he managed throughout TT 2022.
McGuinness ended up ahead of Manxman Conor Cummins on his Padgetts Racing Honda and KTS Honda rider Jamie Coward, while Todd, James Hillier (OMG Racing), SMT Racing’s Rob Hodson and Michael Rutter to round out the top 10 on the Bathams Honda RC213V-S MotoGP replica.
The Sidecars were the final class out on track on Monday, with the FHO outfit of Peter Founds and Jevan Walmsley leading the way with a 117.431mph.
Twelve-time TT winners Ben and Tom Birchall shadowed them on their Steadplan/Hager outfit with a 117.153mph.