Rhyan Grant accepted Sydney FC were "a little bit lucky" after his unorthodox extra-time goal secured victory over Melbourne City in the A-League Grand Final.

The full-back raced onto Luke Brattan's fine pass and chested the ball beyond goalkeeper Tom Glover after 20 minutes of extra time had been played.

The goal sealed a 1-0 win for Sydney, who became A-League champions for a record fifth time and backed up their Premiers' Plate win from the regular season.

The Sky Blues had ridden their luck earlier in the contest, though, Harrison Delbridge having had a goal disallowed for offside by VAR and Craig Noone seeing an effort cleared from in front of the posts.

Reflecting on his winner, Grant told Fox Sports: "It was nice, I was maybe a little bit lucky with it but I thought I'd maybe put the keeper off with the chest rather than the head and it worked, so happy days.

"We didn't start great, we were a bit shaky, we couldn't get the ball on the deck and play football. Credit to City, they started really well and came at us in that first half. Going into the break, we sort of took that as a restart.

"The second half, we were a little bit better - again, probably not at our best - and it was a bit end to end at times, a bit cagey, so we had to ride that out and make sure when we got our chances, we took them.

"City were very good, but we got a little bit lucky, I reckon."

Coach Steve Corica was full of praise for Grant, who won the Joe Marston medal as the best player in the final.

"You could see when he was out a couple of games that we really missed him and he's come back at the right time," Corica said. "He's been sensational all year; he's the best right-back in the country, of course."

Sydney became the first time since Brisbane Roar eight years ago to win back-to-back titles, having also been crowned premiers for the third time in four seasons.

"It's not easy to go back to back," said Corica. "We said before the start that only one team has done that before in the history of the A-League. It really means a lot to this time.

"We set our sights at the start of the year to win the Premiership and to do the double, and full credit to these boys and all the staff - they were sensational throughout the year."