ACAPULCO, Mexico - No.7 seed Heather Watson battled back from a set down to defeat former Top 10 player CoCo Vandweghe in a tough opening round test at the Abierto Mexicano Telcel presentado por HSBC, 4-6, 6-4, 6-4.

In her first WTA-level action since the Australian Open, and her first competitive action in over two weeks after competing for her nation in Fed Cup to begin the month, the British No.2 earned a hard-fought victory in two hours and 31 minutes. 

After coming from a set behind, Watson had to hold off a furious rally from the American, whose ranking currently sits at World No.193 as she works her way back from ankle and foot injuries that forced her to miss the first three Grand Slams of the 2019 season. 

Trailing 5-2 in the final set, Vandeweghe saved three match points - including two on her own serve in the set's ninth game - before ultimately succumbing to defeat in the first-ever meeting between two WTA stalwarts. 

"I'm very pleased with the match today. CoCo is such a great player," Watson said after the match. "She's been a top player for so long, I've known her for so long, and I know how well she can play.

"If I'm honest, I didn't feel like I had much rest. From the Australian Open, I had a week at home, but then I went straight to Fed Cup and was there the whole week. Fed Cup is a very high-stress environment, and I feel like I'm just about recovered to be here now."

Watson started the stronger of the two early on in the match, but was ultimately forced to battle from behind as the two-time Grand Slam semifinalist won six of the last eight games of the opener.

From leading 2-0, with two break points for a double break at 3-0, Watson was pegged back even, and ultimately lost a break advantage twice in the first set.

The former World No.9 found her rhythm on her vaunted serve late in the set, as she served five of her nine aces for the match in the opener, used a love hold at 3-3 as a springboard for momentum into the end of the set. 

"She's been out with injury. She had nothing to lose," Watson assessed. "I don't think she's playing at her best yet, but today was extremely tough. It was tough conditions. It's hot out there, and the ball really gets up high.

"I was just pleased with how well I fought. I wasn't necessarily playing my best either, but I stuck in there. I'm just really enjoying being out there, enjoying my tennis."

The British No.2 started to turn the tide in the second set, helped in part by her own tenacity and more erratic tennis from Vandeweghe both off the ground and on serve. 

The American missed her lone break point opportunity of the set in the second game - which would've seen her open up a 6-4, 2-0 lead - and surrendered serve immediately after, never again earning close to a chance to break in the set. 

In her last four service games of the second set, Watson surrendered just two points on serve, and won the last eight points in her service games to send the match to a decider. 

After both players left the court at the end of the second set, the 27-year-old from Guernsey was the quicker of the two to get her momentum going in the final set.

Watson won 10 of the first 12 points to set the tone, and despite not converting two break chances to lead 3-0, she later earned the insurance break in the seventh game after saving a break point chance against her that would've seen Vandeweghe level the set at 3-3. 

Vandeweghe nonetheless battled with her back against the wall, keeping her main draw debut in Acapulco alive by earning her first break since the opening set after being two points away from defeat at 30-30. In a tense, five-deuce game, the American held on to force Watson to again serve for the match, which she finally did successfully on her fourth match point.

Joining Watson in the second round as early winners on Monday afternoon were No.8 seed Nao Hibino and Russian teenager Anastasia Potapova, each of whom enjoyed contrasting passage through to the second round. 

Hibino eased past Arantxa Rus, 6-3, 6-1, in just over an hour and a half, while Potapova pulled off a stunning comeback from 6-4, 4-0 down to defeat Anna Karolina Schmiedlova, 4-6, 7-5, 6-1. 

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