The England half-back scored his 200th try to help the reigning Super League champions to a 42-20 win over Wakefield in their elimination play-off at Headingley and earned the Rhinos a trip to Perpignan to face Catalan Dragons in Friday's preliminary semi-final.
"I was stuck on 199 for a while there while I was injured but obviously it's a really special moment and an honour to be the top try scorer in Super League," McGuire said. "Hopefully there's plenty more in me and more in me this season."
He added: "Mentally you like to get that first game out of the way. I was a little bit rusty in some areas, obviously fitness-wise, but our form hasn't been that great so it was important that we got a good win.
"Defensively we need to improve a little bit but we scored some nice tries. I thought Kallum Watkins and Zak Hardaker were special and Rob was outstanding, they probably won us the game.
"It real tough. I thought Wakefield were outstanding. They had us on the rack at times but we showed a lot of character to stick in there and come away with a win."
Leeds coach Brian McDermott was thrilled with his side's performance against the form team of the competition and especially delighted for the record-breaking exploits of the club's long-serving half-back.
"It's not easy done that," McDermott said. "Maggys's been overshadowed all year with a couple of little injuries here and there which means he hasn't had the consistent run of form that he'd like.
"But he's a big piece of what we do and he was a big part of that. He was blowing towards the back end of the game but you'd expect that."