American great Serena Williams admitted that she feared her career was as good as over after a leg injury at last year's Wimbledon forced her off tour for a year and saw her ranking plunge to 1,204 in the world.
Williams, 40, made a winning comeback when she teamed up with Ons Jabeur to beat Sara Sorribes Tormo and Marie Bouzkova 2-6, 6-3, 13-11 in the Eastbourne International doubles on Tuesday.
The 23-time Grand Slam singles champion was playing for the first time since a tearful exit at Wimbledon last year. Before she made the surprise announcement of her return last week, murmurs of retirement had grown louder.
But she finally resumed her career, playing with Jabeur at the Wimbledon warm-up event by the Sussex seaside ahead of Wimbledon which starts on June 27.
Williams took a wildcard for the grasscourt major and kicked off her preparations with a doubles win.
"You know what, I'm literally taking it one day at a time," Williams said, adding she "absolutely" had moments of doubt about returning to the Tour.
"I really took my time with my hamstring injury so I'm just not making a ton of decisions after this.
"Did I ever doubt I would return? Absolutely, for sure. I would be dishonest if I said it wasn't and now my body feels great."
Williams won the last of her 23 Grand Slam titles at the 2017 Australian Open and remains one shy of equalling Margaret Court's record for the most major titles.
She reached the final at four majors since returning to the Tour after giving birth to daughter Olympia in 2017 but lost in straight sets on each occasion.
Speculation about retirement gathered pace when Williams released her long-time coach Patrick Mouratoglou in April to train Romania's Simona Halep.
Asked if she saw herself playing into the next year, Williams said: "I don't know, I can't answer that.
"But I love tennis and I love playing, or else I wouldn't be out here, right?
"But I also love what I do off the court, what I've built with Serena Ventures, it's interesting."