The Royals had to come from 0-2 down to beat lower division Bemerton 3-2 in the first qualifying round at The Crest Finance Stadium.
It was a tricky test for Catin’s men against a side full of former Southern League regulars such as Jack Vallis, Eddie Perrett, Jack Smith and Gosport Borough’s record marksman Justin Bennett.
Another intriguing clash is next up at Bemerton’s Wessex Division 1 rivals US Portsmouth on October 10.
But Catlin knows Wessex Premier clubs can go a long way in the Vase, and two of his side - Lee Wort and Pete Castle - won it with Sholing in 2013/14.
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‘After going behind we showed a lot of character to come back,’ said Catlin.
‘I’m looking for a good run in this competition.
‘We’ve got players who know what it takes to win a national competition, and that experience will be vital the further we go.
‘United Services will be a tough game as well.’
Catlin admitted he was worried when Bemerton led 2-0 - a ‘fortuitous’ opener followed by a penalty after assistant manager Lee Molyneaux was guilty of a foul.
‘Lee wrestled their bloke to the ground, I don’t know what he was doing!’ said Catlin.
‘We played Lee at centre half for the first time as Luke Dempsey had a sore back and Craig Hardy a stiff calf.
‘We thought Lee’s experience would be necessary in the middle, but at 2-0 down I was thinking if it was a good idea!
‘Lee did well after that, though, he’s a good organiser - I don’t think Brad Snelling had a shot to save in the second half.
‘We managed it well. At the end we were caught between going for another goal or running the clock down, as we didn’t want to concede again.’
Catlin handed Rudi Plummer his debut after being signed from Moneyfields on Thursday night.
Having had not a full pre-season, the pacy Plummer understandably lacked fitness and was withdrawn in the second half.
He had played his part, however, by winning the penalty which led to Portchester’s equaliser.
Plummer played for three Southern League clubs last season - Blackfield, Moneyfields and Gosport, where he was signed by Molyneaux.
‘Rudi gives us pace which was something we were lacking,’ said Catlin.
‘He’s missed pre-season so we need to bring him up to speed - we’ve got a free midweek so hopefully two training sessions this week will help.’
Catlin praised young midfielder Joe Johnson, on the left side of midfield, after he netted his fourth goal in six games in 2020/21.
‘He was excellent,’ said the boss, who also picked out central midfielder Josh Hanratty - returning after a three-week concussion break - and Rob Evans for praise.
Evans, who had been playing right back, was deployed at left back with Plummer on the left of midfield in the first 45 minutes.