Klaasen (104 off 51 balls) launched himself early on with the bat, scoring frequent boundaries and keeping the scorecard ticking. Siraj was the most economical bowler for RCB with 1-17 from his 4 overs.
In-form Heinrich Klaasen displayed his big-hitting prowess on way to his maiden IPL hundred as Sunrisers Hyderabad recovered from a poor start to post 186 for five against Royal Challengers Bangalore in a crucial match in Hyderabad on Thursday. (More Cricket News) | (Scorecard)
The keeper-batter had six hits over the fence and eight across it during his scintillating 51-ball knock. He forged a 76-run partnership with Aiden Markram (18) before adding another 74 off 36 balls with Harry Brook (27 not out) to take SRH to a competitive total.
Already out of playoff race, SRH once again had a poor start after being asked to take first strike by RCB skipper Faf du Plessis.
As has been the case this season, Rahul Tripathi (15) and Abhishek Sharma (11) frittered away reasonably good starts, leaving Sunrisers at 28 for 2 in the fifth over.
SRH scored just 11 in three overs before the openers milked Wayne Parnell for 16 runs.
However, off-spinner Michael Bracewell struck twice, removing both the openers in his first three balls. While Abhishek hit straight to Lomror at cover, Tripathi found the fine leg fielder off his slog paddle sweep.
Klaasen hammered three fours off Shahbaz Ahmed to power the Sunrisers to 49 for 2 in the powerplay.
Klassen rocked back and pulled every time the ball was short as Bracewell and Harshal Patel was sent across the ropes, while Karn Sharma was dispatched for a 74-metre six.
Karn Sharma was then punished for bowling over-pitched with Klaasen depositing him into the stands. The South African completed his fifty in 24 balls.
While Klaasen was in full flow, Markram managed just run-a-ball 18 before his off stump was pegged back by Shahbaz while he looked for a reverse hit.
Back in the playing XI, Brook then picked up a four and six off Karn Sharma, who bled 21 runs, with Klaasen too lifting him over cover.
Du Plessis' decision to make Shahbaz bowl the 17th over backfired as Klaasen clobbered the first two balls over the bowler's head, while Brook sent one fine.
Parnell nailed the yorkers to concede just seven runs in the next over but Klaasen then plundered Harshal over his head to bring up his hundred. He was dismissed one ball latter while looking for another big shot.
Mohammed Siraj conceded just four runs and took a wicket in the last over.