The Riversiders extended their undefeated run in the NWCFL First Division North to six matches with a 3-2 win against Holker Old Boys.
Victory at the Riverside sees them sitting in seventh place in the table before their home game with AFC Blackpool next Monday.
Freddie Mason and Clark netted twice in as many minutes to put Garstang 2-0 up inside 26 minutes last Saturday.
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Tom Dawson pulled a goal back just before half-time, after which Garstang went 3-1 up through Jake Salisbury on 72 minutes.
Although Patrick Allington halved the lead again, Clark’s players were able to weather the late storm and claim a fourth victory in six outings.
Speaking afterwards, Clark said: “We’ve done really well in the last five games against teams in and around us, it’s important to pick up points against them.
“Going into today’s game, the next two games are home games and it’s important to take advantage.
“We’ve done really well away from home but it’s nice to play at home and use home advantage.
“Holker are in a very good position and they are the teams we need to be beating if we want to keep kicking on.
“We’ve still got a lot to do but we’re heading in the right direction, three points against a team in the play-offs is massive.
“That’s going to give us loads of confidence going into a game against AFC Blackpool, which will be another team above us in the league.”
Victory could have been a more comfortable one but for one area Clark has previously pinpointed as one with room for improvement.
Not for the first time since he took charge on a permanent basis, the player-manager saw his side concede just before half-time, changing the dynamic of the game and giving the opposition a lift.
He added: “We said at half-time we have to be more clinical, myself included, because I should have put us 1-0 up.
“We had a couple of chances at 2-0 to finish the game off and then we conceded at a poor time if I’m being honest.
“You’re 2-0 up with five minutes to go to half-time, you’ve got to see that through.
“We expected them to come out firing (in the second half) and they did, they were probably the better team.
“We got a goal, probably against the run of play, which was a great strike and then we kicked on from there.
“Holker caused us loads of problems, putting the ball in the box, but I think our lads have defended really well.”
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