Ash Barty admits to being a bit fatigued after another hard, though largely successful, week's slog in Madrid - but she reckons she wouldn't have it any other way as she immediately resets her sights on another title in another country.

"Playing a lot of matches is a good problem to have. I feel great," declared Barty after her 14th clay court match in 18 days, against Aryna Sabalenka, in the Madrid Open final proved to be the only one she's lost so far on her European tour.

In what has been a remarkably fruitful two-and-a-half weeks, Barty has played 10 singles matches, six of them being demanding three-setters, and four doubles, lifting two titles in Stuttgart and reaching the singles showdown in Madrid.

Asked if that amount of court time was beginning to catch up with her physically, Barty, who's flown straight off to Rome for the Italian Open, said: "Yeah, it's a good problem to have.

"I think any time you can play a lot of matches and a lot of tennis, it means you're putting yourself out there over and over again.

"Of course, there was a little bit of fatigue. Aryna also played a lot of tennis. There wasn't much physically in it. It was more she was able to take her opportunity at the end."

In an engrossing final that lasted one hour 40 minutes, Barty looked the stronger player for much of the third set before a familiar starburst of inspiration over the final three games powered Sabalenka home.

It was a close-run thing, reckoned the world No.1. "Now I feel like we have another opportunity in Rome to try do the best we can there," she added.

The action's already under way in the Foro Italico with Australia's No.2 Ajla Tomljanovic joining Barty in the main draw when she came from a set down in Sunday's qualifier to defeat tough German Laura Siegemund 6-7 (5-7) 6-3 6-2.

There's a loaded field with Serena Williams back in action for the first time since her Australian Open semi-final defeat by Naomi Osaka, with the pair set to meet at the quarter-final stage.

For Barty, there's also a potential fourth tussle this year against Sabalenka, with whom she's now enjoying a compelling rivalry.

Barty leads 2-1 this season, though it's now 1-1 in 2021 finals and locked at 4-4 overall, with the pair set to meet in the quarter-finals this week.

"All of our matches are always close. There's always just a couple of points, a couple of games," said Barty.

"It's always a very fine line against the best players in the world that you have to kind of tread. Sometimes you have to take that risk, other times they're going to find a way to win the match.

"That's the beauty of our sport. Every time you step on the court, there's an uncertainty.

"You go out there and you just try your best on that given day. If it's enough, it's enough. If it's not, that's all right as well."