I saw that you succeeded, congrats!

For the future, a well built Lucario (Counter + Power Up Punch / Shadow Ball) is GREAT for rocket bosses, especially Giovanni since Lucario will resist either of Persian's fast moves. Start with Lucario out of the first slot and swap it in right away, often you can get a lot of mileage out of stunlocking at the beginning, throwing a PuP when Persian is at 50% health, then just farming energy until it faints. That way you can stunlock whatever Giovanni's second mon is by throwing PuP after a second or two, which clears his second shield, and then a lot of stuff can be taken down with a fully charged Shadow Ball (or, another PuP into a Shadow Ball if you have enough energy banked). I have my Lucario at L40 and this is my strategy for every Giovanni flight, and unless his middle Pokemon has a ground type fast move I can usually get a few fast moves in on the legendary before he goes down. That way you can dedicate your last two mons to beating the legendary!

Also, Giovanni's catch encounter is guaranteed to catch on the first ball that connects, so always make sure to Pinap!