Keegan-Michael Key beats Venus Williams and Rob Gronkowski on season finale of Game On show on CBS

Keegan-Michael Key beat Venus Williams and Rob Gronkowski at an athletic challenge in the surprising season one finale of the Game On! show on CBS.

For a round called Speed Gun Smash, the two sports legends ran between electric poles that measured their velocity, with each of them trying to be the fastest.

Venus, 40, changed into sports gear to tackle the run, propelling herself as fast as she could go and leaping so hard through a sign at the end that she nearly missed the safety pad.

Rob, 31, was as enthusiastic as always, taking a wild run that saw him jump through the sign in a burst of energy, then pump his fists in victory.

Venus notched 14 miles per hour, while Rob came in at 14.2 mph, ready to take the crown.

‘Anyone else want to have a try?’ show host Keegan-Michael, 49, asked the room.

Comedian Bobby Lee, 48, on Team Gronk, led everyone in cheering ‘Keegan! Keegan!’ and the host magically found an athletic headband to wear.

Within seconds, it was clear Keegan-Michael was the fastest runner, as he zoomed to the end of the track and scored a speedy 15 mph.

‘Oh my god! He got 15!’ Bobby yelled in disbelief.

For the last show of the season, Team Venus included comedian Ian Karmel, 35, and guest star Terrell Owens, 46, the NFL Hall of Famer.

Team Gronk included Bobby and former Saturday Night Live star Kevin Nealon, 66.

For their first challenge, Can You Hit It?, Venus and Rob tried to knock trophies off their teammates’ heads.

Rob hurled five footballs at Bobby to get the job done, and only hit him in the crotch once.

Venus smashed just three tennis balls at Ian to win.

Terrell loved it, crowing, ‘Did you see that?’ and running to hug Venus.

For their second challenge, teams matched retired NFL stars to their end-zone dance.

Keegan-Michael asked Rob if he knew other football players’ dances well.

‘Not really,’ Rob cracked. ‘When they played versus me, they never got the chance to celebrate, because they never scored.’

Both teams tied for the round, with each aware that Victor Cruz, 33, did salsa in the end-zone, Steve Smith 41, made rowing motions, and Chad Ochocinco, 42, did an Irish jig.

During challenge three, Speed Gun Smash, Keegan-Michael asked Kevin how his famed SNL character Franz, of the muscleman duo Hans and Franz, would describe Rob.

‘This man is the perfect embodiment of pumpitude, at one time,’ Kevin said, in character. ‘But he has let himself go. He’s lost 20 lbs. Now he’s a skinnymalink. He’s just a pile of kindling.’

Of Terrell, he said, ‘His name spells it out: ‘T.O.’ Too wimpy.’

Team Venus and Team Rob each tried their hand at the racing challenge, but Keegan-Michael decimated the competition.

Challenge four required teams to match famous athletes’ restaurants to their reviews.

Only Team Gronk knew that baseball legend Albert Pujols, 40, once owned a place that had a waitress serve cheese she’d dropped on the floor.

No one guessed that John Elway’s restaurant once boasted a visit from rapper Waka Flocka Flame, 34, or that Shaquille O’Neal’s ‘thin but wide’ fries earned raves.

The final challenge, Brains Versus Brawn, asked teams to dunk 10 balls over a pool of water as the opposing team answered sports questions.

Team Venus got more answers and won the game, notching 15 points to Team Gronk’s 13.

As punishment, Team Gronk had to perform ‘an Irish jig of defeat’ with real Irish dancers.

Watching them, Keegan-Michael observed that Rob was actually doing the Running Man.