Johanna Konta saved three match points as she battled back to defeat Wang Yafan 4-6 7-6 (0) 6-4 in their first-round match at the Morocco Open in Rabat.
The British number one had helped her team-mates earn promotion to the Fed Cup World Group for the first time since 1993 with victory against Kazakhstan in London over Easter.
After losing the opening set as both players' serve faltered, Konta again showed great determination to recovery in her first match of the clay court season, denying the Chinese player three match points to force a tie-break.
Konta, the world number 47, closed out the second set with a love tie-break only to then trail 3-1 in the decider following an early break by Wang, who was celebrating her 25th birthday.
The Briton, though, forced a break back of her own to level up at 3-3 and then again to serve for the match, only to fail to hold before finally delivering a second match point on Wang's double fault.
Konta, the tournament's seventh seed, will go on to play Romanian Ana Bogdan in the second round.
Speaking in her post-match interview on court, broadcast by the WTA, Konta said: "I am very proud of myself for the way I competed, it was a tough match for both of us.
"I lost that first set and then my opponent had three match points in that second set, so I am very happy to have battled through and found a way to win that second set, then come back from 3-1 down in that last set.
"I also had a match point at 5-3, so there was very little in the match for it to go either way, I am just very happy I made it through."
Konta added: "It is my first match on the clay for this season, so that presents its own challenges. I am just very happy to have had such a good match for a first match.
"There is no easy match here, so I am anticipating a really good battle (in the second round)."