The road to a first ATP Tour win has been long and arduous for Billy Harris.

On Tuesday, he secured a 6-4 3-6 7-6 (7-5) win against Switzerland's Marc-Andrea Huesler at the Sofia Open.

Two months short of his 29th birthday, and almost 10 years after his professional debut, Harris's perseverance has paid off.

"It's definitely been a slow process," Harris, who plays Germany's Jan-Lennard Struff in the second round on Wednesday, told BBC Sport.

"To finally get my first main-draw win feels so special."

Like many players scrabbling to make ends meet in the lower rungs of professional tennis, Harris has faced significant obstacles which left him contemplating whether it was all worth the hassle.

The long drives around Europe - a 3,000-mile trip from Portugal for a nine-week stint in Poland still makes him shudder - took their toll.

And then there were the injuries - most seriously in 2018 when he fell off a treadmill in Thailand and spent almost eight months sidelined with the subsequent groin and back problems.

Four years ago, having made a comeback and with his world ranking stuck at around 600, he was ready to quit the sport.

"I was always around top-five in my age group in the juniors but when I started off in the Futures it took a while to get going," he said.

"I was travelling around in my Transit van for three and a half years, with a bed in the back, cooking on the roadside and parking up in McDonalds' car parks.

"A couple of injuries set me back, particularly when I fell off the treadmill in Bangkok. I tore my groin and dislocated the sacroiliac [joint] in my back, which took a while to get right."

The encouragement of one of his sponsors - Mark Smith, who runs a sofa company and whose son Harris teaches tennis to - was the catalyst to continue.

"Mark said 'keep playing for another year'. He supported me and has been backing me since then," Harris said.

"In the last two years I've started to win a few events, found a bit of form and made steady progress."

Winning five titles on the Futures tour - the lowest rung of the men's professional tours - and stepping up successfully to the second-tier ATP Challenger Tour led to his first tournament at the highest level in Sofia.

Coached by his dad Geoff, and with Britain's Davis Cup captain Leon Smith providing support, Harris came through qualifying before beating Huesler.

Significantly, the win means he will be ranked high enough to play in the qualifying rounds of next year's Australian Open.

Before that, Harris will travel with Great Britain to the Davis Cup Finals in Malaga later this month, providing support as a hitting partner for a squad including three-time Grand Slam champion Andy Murray.

It was also a role he fulfilled when Britain qualified for the last eight at a group-stage event held in Manchester in September.

The experience of practising with Murray, plus fellow top-100 singles players Cameron Norrie, Dan Evans and Jack Draper, provided further confidence for Harris.

"Hitting with those guys and training with them was a great experience," added Harris.

"It was good to hit with that kind of level and probably helped my results as well. It gives you the confidence you're not that far off the level required.

"Hopefully I can keep pushing on and keep chipping away at the ranking."