STEFFI HAS BROKEN MY HEART; BITTER: ANGER OF GRAF'S DUMPED LOVER.
Racing driver Michael Bartels is devastated that she has left him for fellow tennis ace Andre Agassi.
Now the Frenchman has vowed to get even with the former Wimbledon champion.
He said: "I'd rather not say what I felt when I heard that she wanted to go down a new path after seven years with me. What I feel is very private."
And he warned Steffi: "When I do think I am able to speak then I will. And I will speak forcefully."
Bartels revealed Steffi's love for Agassi came like a bolt out of the blue.
He said: "I had no idea Steffi and Andre were an item. I had never seen him around and didn't even know they were close friends.
"I suppose I would always have been the last to know, I really never suspected. It's left me stunned."
Bartels added: "It's clear to me now that all the time I was travelling with my racing Steffi and Andre were talking a lot and also writing to each other. The whole thing is really hard to swallow."
Agassi and Graf's love blossomed on the tennis circuit as they travelled the world together playing tournaments and exhibition matches.
The pair somehow managed to keep their relationship hidden from the prying eyes of the gossip columnists.
Graf, who has also dated Manchester-born Simply Red star, Mick Hucknall, recently announced her retirement from tennis. Meanwhile, Agassi regained the World No1 ranking after winning the US Open at Flushing Meadow in August.
Las Vegas-born Agassi, 29, who claims to be a devout Christian married actress Brooke Shields in 1997 but he divorced the Hollywood star this year after a series of bitter arguments.
Steffi, who won Wimbledon seven times, has now said she wants a "new beginning" to her life - with Agassi.
She said: "I believe I can fly now. My friend Michael is no longer around but we experienced a lot together.
"Now we have parted we must both go our own way. I am now looking forward to spending time with Andre."
The first clues about the pair's romance emerged in New York in early August when Steffi stole in to watch Andre's epic US Open victory over Todd Martin.
Hours later, the American took her out for a meal to celebrate, fuelling speculation that they had finally become an official item.
Graf's father, Peter, recently spoke of his sadness over his daughter's break-up.
He said: "As a racing driver, Michael had many temptations. But he never succumbed. He was a very honourable guy. I'm very sad they've split up after seven years."