1. If I Told You That

2. Get It Back

3. You Light Up My Life

4. Saving All My Love for You / The Greatest Love of All / All at Once / You Give Good Love

5. Superstar / Never Too Much

6. Step by Step

7. Wishin' and Hopin' / Alfie (With Dionne Warwick)

8. Heartbreak Hotel / It's Not Right but It's Okay

9. My Love Is Your Love

10. I Go to the Rock (With Natalie Cole)

11. This Will Be (With Natalie Cole)

12. I Wanna Dance With Somebody (Who Loves Me)

13. How Will I Know

14. I Will Always Love You

15. That's What Friends Are For (With Natalie Cole & Dionne Warwick)

Officially, Wednesday night's concert in Hamburg, Germany, was billed as the "Soul Divas": Dionne Warwick, Natalie Cole and Whitney Houston. But by evening's end, reports PEOPLE, the show belonged to Houston.

The sellout crowd of 12,000 at the town's Color Line Arena cheered loudest when Houston, 40, appeared onscreen in video clips shown between sets by Warwick—who is Houston's aunt—and then Cole, 55, who followed the 62-year-old "Do You Know the Way to San Jose?" singer on the program.

Two hours into the show, when Houston finally appeared onstage, the crowd rose to its feet.

"It's been such a long time since I performed in Germany—too long, thank you," the six-time Grammy winner told fans. "It's been such a long time since I performed, period," she added with a shrug.

The singer, who spent time in a substance-abuse facility in March and has not toured since 1999, was dressed in a figure-hugging silvery-gray corseted gown that she had to keep pulling up. At one point, Houston asked Warwick to entertain the audience while she scurried offstage to adjust her dress as several security guards blocked her from public view.

"No, the people didn't pay enough for that," Warwick hooted as she caught sight of what Houston was doing.

Joked Houston as she returned center stage: "We're not gonna do a Janet Jackson here in Germany."

The show was, as Warwick called it, "a trip down memory lane" for all three singers. Houston's husband, Bobby Brown, escorted her on and offstage and watched from a seat in stage left as his wife delivered her greatest hits, including "How Will I Know" and "Saving All My Love for You."

She also pulled Brown into the spotlight for a few steps during her rendition of "I Wanna Dance with Somebody." She closed her set by kneeling in the center of the stage, as if in prayer, before suddenly popping up and blowing kisses goodbye.

She returned 15 minutes later for a finale with Cole and Warwick—the only time all three "soul divas" appeared together. Their song: "That's What Friends Are For."

The German mini-tour will continue Friday in Munich, and on July 22 Houston will make her Chinese debut in Shanghai.