The 22 year old has been playing off invites this season, with four top tens leaving him at 103rd in the Race to Dubai Rankings presented by Rolex when he teed it up in Vilamoura.
An opening round of 63 set the tone for the week and when he went off in the final group on Sunday, he had a two-shot lead as he looked to become the first wire-to-wire winner of the 2018 European Tour season.
A closing level par 71 meant Herbert finished the week in a tie for second behind Tom Lewis but the result moved him up to 64th in the Rankings and he will end the season secure in the knowledge he has his playing privileges for 2019.
“The goal at the start of the year was to get a main Tour card and we’ve done that, so that’s a pretty good feeling,” he said.
“Moving up the World Rankings is obviously the goal. Give myself the best chance by the end of next year to make the Presidents Cup team. If I can keep doing this I’m not going too far wrong I hope.”
Herbert was one shot behind playing partner Lewis stood on the 17th tee and when the Englishman put his tee-shot in the water on the par five, it looked like the door was open.
However Lucas' third after laying up was a long way from the hole and he could only make par, with Lewis holing a 35-footer to salvage his own.
Herbert put his tee-shot in the water on the last to close with a double-bogey and there was a natural sense of disappointment despite an excellent week.
“It kind of feels like all of the air has come out of me,” he added. “It was looking like it could have been a two-shot swing on 17 and then Tom goes and holes that putt and I hit a horrible tee-shot down the 18th.
“I can’t be too critical of myself and I have to try to take the positives at the moment even though it’s not ideal not winning after carrying a lead into the last round. If I keep putting myself here enough times, surely one of them has to work out?
"It’s hard with golf, you don’t win very often. It’s pretty clichéd but you have to try to take the positives. I played three really good rounds under pressure when I needed to to get my card, so I’ll try to think about that when I look back at this week.”
Eddie Pepperell finished alongside Herbert at 19 under as his run came up just short.
The Englishman made three birdies on the back nine to get within two of the lead but he dropped a shot on the last as he achieved a fifth top ten in seven starts.
That form pushed him to the brink of the Ryder Cup Team and while he will not be teeing it up next week, he will be present at Le Golf National.
“If you shoot that round on a Thursday or Friday you would be very frustrated,” he said. “On a Sunday in the position I'm in, it's not a terrible round of golf. I just wasn't quite good enough.
"I'm going to The Ryder Cup on Saturday, which I'm looking forward to. I've never been to a Ryder Cup before and I'm desperate to see this one especially, because my expectations for it, as everyone, are high.”